title: xcode change bundle identifier to overwrite old app
body: <p>I have a old version of an app created by someone else with a different bundle id, I would like to update this so users who have downloaded it will get the new version of the app.</p>
  
  <p>Would it just be a case of changing the bundle id in xcode and uploading it over the old app?</p>
  
  <p>How would I do this in xcode, can I copy my project so I can rename it?</p>
  
  <p>For future updates would I need to update two versions? could I link them somehow to avoid this?</p>