Mine was easy to replace. You don't do anything with the screws. There is a slot (at the top I think) that you put a straight-slot screwdriver into and push down (I think) to release a plastic tab. Then you pull forward on the entire touchpad and it comes out of the housing. There is a multi-pin connector on the back.
I had two fail in the first 16 months and Lippert replaced both for free even though one was out-of-warranty. My problems had to do with certain buttons becoming intermittent. Had to press them multiple times to get a response.