new u joints and ball

I want to replace my u joints the front must have been changed because it's greaseable. The two rears are not i have 102,000 and no longer trust the rears. although all seems well. I think they maybe factory. My question is, how do i get the back part of the shaft off? there is a C clip in the way and I can't seem to get a wrench tight on the bolts. not to mention they are really tight. if I use an extention I cant put enough pull on to break the bolts loose. Now what about the ball? 
thanks
gTAGG

If you are wanting to replace the double cardon u-joints and the centering ball kit, I would suggest you let a shop do it, this is not an easy job unless you have the tools and are very mechanicals.
Yes, I would suggest you replace all your old u-joints because of their age.

Thanks Mike, I was thinking the same thing. just wondering about cost. you lived in AZ at one time, know anyone? I do everything on my truck, but this seems more of a pain. it's hard to do these things on the garage floor
gTAGG 

There are a few drive line shops in Phoenix, and probably alot of small tranny shops that would probably do it.