dually fenders

I'm trying to remove the fenders from my 86 crewcab. I took the cover plate off the inner fenderwell to gain access to the nuts on the fenders. I can just get my hand in the opening, and theres no way I can get my arm in there to get to the nuts at the top of the fender. how is this done ? any help would be appreciated.

if the bed is off the truck the best thing to do is stand the bed on the end where you can see what your doing....i used a 3/8 drive ratchet and a ratchet wrench last time i pulled mine off.....takes alot of cussing lol

Thanks for the help Comegetsome, the bed is still on the truck. bed needs some work, so I'm thinking about using a 2x4 and pry out the bedside just enough to get my arm in there, and see what I can do. the cussing started when I looked at it.