Rep Power: 0

I used this car very seldom and I just had it relocated from NJ to Fl where now I live full time. I just noticed that I cannot open the trunk with the key but it opens fine when I use the floor lever. Another problem I have , the small screw in the key has a sripped head and I cannot change the battery. Any idea how to fix these problems. Thanks for any input you might have

 
Rep Power: 518

I'd first get some penetrating oil or rust buster type stuff in a spray can with a thin straw on the nozzle, and shoot a liberal amount inside the trunk lock cylinder. (hold the little door to the side with something so the straw can be inserted). Let it soak in a while then start working the key and see if it will free up and begin working.
Otherwise, you might have to take the cylinder out and take it apart to free it up.

Stripped screw in the key is a tricky to fix without breaking the plastic, but sometimes it can't be done without breaking it or the plastic.
I heat the blade of the key JUST ENOUGH to loosen the loctite on the screw but (hopefully) not hot enough to melt the plastic. Then beat a #0 JIS screwdriver bit into the screw cross and see if it will bite in and turn. If not, a small Left-hand drill bit and a very slow drill might get it to back out.

 
Rep Power: 102

you are using a regular key, not the valet key, correct?

 
Rep Power: 518

Good point.
I forget the simple shuff rather often lol

OP:gray is usually the valet key..

 
Rep Power: 0

Thanks guys for reply. I managed to drill the head of the screw and opened the plastic. Then with a small plier I grabbed the screw and turned it out.
The hardware store did have a small replacement screw. Regarding the trunk I slightly bent the whole solenoid assembly down and the trunk opens with the key and lever effortlessly every time ( I saw that on youtube)