Add info about providing the .pem file if you've previously

chrome/common/extensions/docs/static/packaging.html

 <div id="pageData-name" class="pageData">Packaging</div>
 <div id="pageData-showTOC" class="pageData">true</div>
 
 <p>
 This page describes how to package your extension.
 As the <a href="overview.html">Overview</a> explains,
 extensions are packaged as signed ZIP files
 with the file extension "crx"&mdash;for example,
 <code>myextension.crx</code>.
 </p>
@@ skipping 62 matching lines @@
 </ol>
 
 
 <p>
 <b>Do not lose the private key!</b>
 Keep the <code>.pem</code> file secret and in a safe place.
 You'll need it later if you want to do any of the following:
 </p>
 <ul>
 <li><a href="#update">Update</a> the extension</li>
-<li>Upload the extension using the
-<a href="https://chrome.google.com/webstore/developer/dashboard">Chrome Developer Dashboard</a></li>
+<li><a href="#upload">Upload</a> the extension to the Chrome Web Store</li>
 </ul>
 
 <p>
 If the extension is successfully packaged, you'll see a dialog like this
 that tells you where to find
 the <code>.crx</code> and <code>.pem</code> files:</p>
 </p>
 
 <img src="images/package-success.gif"
   width="554" height="208" />
@@ skipping 33 matching lines @@
   <li>
     Click <b>OK</b>.
   </li>
 </ol>
 
 <p>If the updated extension is successfully packaged, you'll see a dialog like this:</p>
 
 <img src="images/update-success.gif"
   width="298" height="160" />
 
+
+<h2 id="upload"> Uploading a previously packaged extension to the Chrome Web Store</h2>
+
+<p>
+You can use the Chrome Developer Dashboard
+to upload an extension that you've previously packaged yourself.
+However, unless you take special steps,
+the extension's ID in the Chrome Web Store
+will be different from its ID in the package you created.
+This different ID might be a problem if you've
+distributed your extension package,
+because it allows users to install multiple versions of your extension,
+each with its own local data.
+</p>
+
+<p>
+If you want to keep the extension ID the same,
+follow these steps:
+</p>
+
+<ol>
+  <li> Rename the private key that was generated
+    when you created the <code>.crx</code> file to <code>key.pem</code>. </li>
+  <li> Put <code>key.pem</code> in the top directory
+    of your extension. </li>
+  <li> Compress that directory into a ZIP file. </li>
+  <li> Upload the ZIP file using the
+    <a href="https://chrome.google.com/webstore/developer/dashboard">Chrome Developer Dashboard</a>. </li>
+</ol>
+
+
 <h2>Packaging at the command line</h2>
 
 <p>
 Another way to package extensions
 is by invoking <code>chrome.exe</code> at the command line.
 Use the <code>--pack-extension</code> flag
 to specify the location of the extension's folder.
 Use <code>--pack-extension-key</code>
 to specify the location of the extension's private key file.
 For example:
 </p>
 
 <pre>
 chrome.exe --pack-extension=c:\myext --pack-extension-key=c:\myext.pem
 </pre>
 
 <p>
 To suppress the dialog,
 add <code>--no-message-box</code> to the command.
 </p>
 
 <h2>Package format and scripts</h2>
 <p>
 For more information on the format, as well as pointers to scripts you can use
 to create <code>.crx</code> files, see <a href="crx.html">CRX Package Format</a>.
 </p>