It took me a minute....but I got it. The difference between boards and bed. Ha! You can assemble the boards into the bed with the bed off the truck. When you do that there is little effort to get at the bolts and nuts and washers. Look at the pics on the Mar-k site and put the cross members in with the boards. When you are done it can be lifted and placed over the truck frame. You will only have 6 bolts to attach and they are easy to get to. One in each corner with a block and rubber pad to the frame. The last 2 are on the back cross rail that is not the tailgate. The forward cross rail is a floater and is not bolted to the frame. All of the bolts that go thru the side angle strips just clamp the boards in place. Look at those pics it will become clear.

Steve H