I did not do any body work unless you count putting dents in it before the body shop fixed it. I built the engine, rebuilt the suspension and did a host of other improvements, but I know my limitaions and I do not do body repairs, recover seats, fit convertable tops or replace windshields.
The rear bumper is easy. There are 4 mounting points. One on each side - there are a pair of large dimple in the fenders for the side mounts , you have to drill holes in them - watch out for the gas tank! and there are a pair of holes in the lower rear panel for the rear bolts.
The front bumpers were much more difficult as I used a Euro mounting bracket. I had to cut off the mounting plates for the bumper shocks and then cut away some more metal before the new bracket could be welded in place. I had help from a guy with cutting and welding equipment.
Ed