Undo the wiring to the tail lamp, remove the rear fenders, undo the bolts connecting the bed to the frame, and lift upward. Really NOT that difficult!!
I believe there are 4 bolts that fasten the bed to the heavy wood sills (the wood sills are bolted to the frame). I think these are the only bolts that need to be removed to lift the bed off the pickup. The bolts can be seen on the outer part of the bed lip. the front bolt is about 3" or 4" from the front of the bed and the rear bolts are back about a foot and a half and can only be seen inside the rear wheels.
Rusty Nelson
I think the frame only has 2 holes that the bed bolts to - the rearmost bolts. These bolts (one one each side) go through the bed rear hole, through the wood sill and then through the bolt holes at the ends of the rear frame crossmember. The front 2 bolts in the bed (one on each side) go through the wood sill only. The wood sill is bolted to the frame with another pair of bolts, but the bolts don't go through the bed. I am attaching a picture showing the 2 bolt holes in the bed that are used to fasten the bed to the frame (rear) and wood sill (front). The front of the bed is on the right side of the picture.
Rusty Nelson
Be careful. It is rear end heavy, and when the last bolt is out it will tip off of the frame to the back. Be sure to support it in the back, or have your lifting set up already connected to catch it.