Well, it's a pain. The same screws gave me issue but I was prepared in advance and just heated them until the thread lock gave out, then it was easy. It's not tough, just tedious. The results are worth it though since now I can *see* what's behind me! Good luck!
Interested in getting a backup camera to work with stock nav..did you have the same trouble as holey donuts with removing the screws on the side of the head unit or does the ventura system bypass having to do this. Id like to do it myself but it seems really tough