I noticed that the bumpers, the ones that bolt on the upper control arm, are hollow and the drivers side is completely off.

Question is, how do I replace them with out removing the upper control arm.

The little nut I can put a wrench on it but cannot get enough clearance to move the wrench to remove the nut to replace it.

 

Well you should be able to. The only way I could do mine when I put the new ones on was like a half a turn at a time with an open end wrench, talk about a royal pain. However if you have a gf thats more than happy to get the chance to help you work on your truck (like mine ) Then that's the perfect job for her. It takes patience which is something I come up a little short of. It's a pain, but it can be done

 

Much easier to undo the upper 'A' to do this. I have done it both ways, many times but...the way to do it is to undo the upper 'A' frame-word to the wise-check out your upper ball joint before you do this just in case while you're in there you need to do that-never would be easier...Jerry