title: How delete Documentation "iOs 4.2 Library" in XCode 4
body: <p>HI. My XCode 4.0.1 have a lot of documentation downloaded. I have</p>
  
  <ul>
  <li>iOS 4.2 Library</li>
  <li>iOS 4.3 Library</li>
  <li>Mac OS X 10.6 Core Library</li>
  <li>Mac OS X Legacy Library (uninstalled)</li>
  <li>Xcode 4.0 Developer Library</li>
  </ul>
  
  <p>I want to uninstall 4.2 Library because it is old. But the "minus" sign is disable and "Delete Documentation Feed" is disable too. So, there are no other way to delete it.</p>
  
  <p>Someone know how to do this?</p>