changing forward slash key to return key
You can use Karabiner with a private.xml such as the following:

&lt;?xml version="1.0"?&gt;
&lt;root&gt;
  &lt;item&gt;
    &lt;name&gt;Changing forward slash key with return key&lt;/name&gt;
    &lt;identifier&gt;private.slashreturn&lt;/identifier&gt;
    &lt;autogen&gt;
      __KeyToKey__
      KeyCode::SLASH,
      KeyCode::RETURN
    &lt;/autogen&gt;
  &lt;/item&gt;
  &lt;item&gt;
    &lt;name&gt;Changing tilde key with left shift&lt;/name&gt;
    &lt;identifier&gt;private.tildeleftshift&lt;/identifier&gt;
    &lt;autogen&gt;
      __KeyToKey__
      KeyCode::BACKQUOTE,
      KeyCode::SHIFT_L
    &lt;/autogen&gt;
  &lt;/item&gt;
&lt;/root&gt;