Broke mine trying to remove it. You are correct, the Ford Oval clips onto the housing and does in fact "pop off". It has plastic tabs behind it. With care - you should be able to remove without breaking them.
Behind the oval, the housing is held on to the tailgate by two screws, and the backup camera is secured by a plastic clip. These aren't difficult to remove and reinstall, but I would be very careful with the oval. If you do break it, a replacement only costs about $25 shipped. Some might say it's a good idea just to order it ahead of time in case it does break, so you don't have to drive around without it like I did for a while.