I did my 6' myself. I just slid it back enough to get to the front tank.
There's some sharp edges, so get some real thick leather gloves. It really had to put some *** into it to get my bed up, off the bolt holes, and to slide it back enough to get to the fuel pump. My 6' bed wasn't THAT bad, just very awkward. When I reinstalled it, I tried just getting underneath it and "benching" it up to get the shims back in... It seemed a lot easier that way, but watch out for falling dust, dirt, and rust that WILL find it's way into your eyes.