Click on Back Up Now Wait for the back up to complete Click on Restore iPhone... If the Restore button is greyed out, you haven't signed out of Find My on your iPhone. As soon as you have, the button is available and clicking it means your Mac will completely erase your iPhone. It will then offer you the choice of setting the iPhone up as a new device, or restoring it from a previous backup. This is why it's important to have just done a backup as part of this process. Seemingly the Mac will offer you any iPhone backup that it has, regardless of what Apple ID you're signed in as. Consequently, in