title: Magento - remove block using update XML
body: <p>How do I use a layout xml file to remove an already existing block? Specifically, I want to remove the block named "currency" from the block named "top.switches". It is being inserted in the directory.xml file, like this:</p>
  
  <pre><code>&lt;default&gt;
      &lt;reference name="top.switches"&gt;
          &lt;block type="directory/currency" name="currency" before="store_language" template="directory/currency.phtml"/&gt;
      &lt;/reference&gt;
      &lt;reference name="head"&gt;
          &lt;block type="core/template" name="optional_zip_countries" as="optional_zip_countries" template="directory/js/optional_zip_countries.phtml" /&gt;
      &lt;/reference&gt;
  &lt;/default&gt;
  </code></pre>