I want to remove the bed of my 1988 pickup but the bolts just spin when I try to loosen the nuts. Any ideas?

Liquid wrench

You could tack the top of the carriage bolts in the bed. Just a thought

Cut the bolts off and replace. Chances are if the carriage bolts are spinning the square hole is now a round hole and improvisation will be required

Once they start spinning, I always have to cut the bolts off. Usually the tab up in the bed has bent and no way to access it until the bolt is cut off and then lift the bed to get the tab out of the slot. I have cut many a bolt on the bed.

Cut them off? I am afraid if I use a torch, the whole bed will catch on fire. I am not sure how else to cut them off. I have not ruled out a torch.

Thank you for your advice.

Plasma cutter or a swazall

I use an electric cut off saw if the bed bolts have spun a few times to get the blade in there. I also have a pea grinder with a small blade on it that lets me get to some if there is not much room to get access to them.