How to disable built-in keyboard on OS X 10.9.1?
You might use a private.xml like this with KeyRemap4MacBook:

&lt;?xml version="1.0"?&gt;
&lt;root&gt;
  &lt;devicevendordef&gt;
    &lt;vendorname&gt;APPLE&lt;/vendorname&gt;
    &lt;vendorid&gt;0x05f3&lt;/vendorid&gt;
  &lt;/devicevendordef&gt;
  &lt;deviceproductdef&gt;
    &lt;productname&gt;LAPTOPKEYBOARD&lt;/productname&gt;
    &lt;productid&gt;0x1234&lt;/productid&gt;
  &lt;/deviceproductdef&gt;
  &lt;item&gt;
    &lt;name&gt;test&lt;/name&gt;
    &lt;identifier&gt;test&lt;/identifier&gt;
    &lt;device_only&gt;DeviceVendor::APPLE, DeviceProduct::LAPTOPKEYBOARD&lt;/device_only&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x00, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x01, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x02, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x03, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x04, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x05, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x06, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x07, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x08, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x09, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x0a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x0b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x0c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x0d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x0e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x0f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x10, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x11, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x12, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x13, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x14, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x15, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x16, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x17, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x18, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x19, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x1a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x1b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x1c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x1d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x1e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x1f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x20, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x21, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x22, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x23, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x24, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x25, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x26, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x27, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x28, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x29, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x2a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x2b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x2c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x2d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x2e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x2f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x30, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x31, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x32, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x33, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x34, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x35, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x36, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x37, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x38, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x39, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x3a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x3b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x3c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x3d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x3e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x3f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x40, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x41, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x42, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x43, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x44, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x45, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x46, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x47, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x48, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x49, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x4a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x4b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x4c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x4d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x4e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x4f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x50, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x51, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x52, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x53, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x54, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x55, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x56, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x57, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x58, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x59, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x5a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x5b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x5c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x5d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x5e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x5f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x60, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x61, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x62, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x63, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x64, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x65, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x66, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x67, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x68, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x69, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x6a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x6b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x6c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x6d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x6e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x6f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x70, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x71, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x72, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x73, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x74, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x75, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x76, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x77, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x78, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x79, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x7a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x7b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x7c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x7d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x7e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x7f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x80, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x81, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x82, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x83, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x84, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x85, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x86, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x87, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x88, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x89, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x8a, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x8b, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x8c, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x8d, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x8e, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x8f, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x90, KeyCode::VK_NONE&lt;/autogen&gt;
    &lt;autogen&gt;__KeyToKey__ KeyCode::RawValue::0x91, KeyCode::VK_NONE&lt;/autogen&gt;
  &lt;/item&gt;
&lt;/root&gt;


Replace 0x1234 with the ID shown by EventViewer (/Applications/KeyRemap4MacBook.app/Contents/Applications/EventViewer.app).