title: Android Studio - File is read only
body: <p>I've downloaded a library from github and I would like to edit the class to suit my needs. But Android Studio won't allow me saying &quot;File is read only&quot; when I try to type and edit the class.</p>
  <p><img src="https://i.stack.imgur.com/fLy7o.png" alt="linked image so you can see what I mean" /></p>