Is it just the lens that is shot or the whole assembly?
Either way your post was enough to spur me to fix that burned out bulb in mine.
The lens can get pretty brittle from sitting in the sun all the time. Be careful when removing it. That rubber seal can be stuck pretty good. After you have removed the two retaining screws, carefully pry up a corner and use you fingertips to work the bottom loose. Gentle pressure and it will pull free.
Don't get carried away tightening things up. Snug is good enough. Make sure those rubber seals on the screws are in place. Those will seal out moisture and help to retain the screws without excessive tightening.
If you have to remove the whole assembly, it looks to me like you are going to need to pull the headliner loose. Mine has the Bravada entertainment center so I'm not going to dig in that deep for you. Sorry.