I know that one side si removed by 4 screws (passenger's side I think. the one with the step), but the other (Driver's side?) doesn't have the same screws. I want to put the step on both sides of a brat. This is on an 82 if that makes any difference.

Mine on my 82 was just a snap in plate that took some effort to get under but once I got a flat screwdriver under it it popped right off. The holes were there so I snapped in the clips and installed a real step in the hole for one on each side, I take it that is what you are trying to do?

That is precisley what I was taslking about. Got pics of the removal?

there's also a sheet metal brace to be welded into the car to hold your weight as the plastic step itself isn't strong enough. check the stock step side to see.

You can pull the acces panel inside the bed and get to at least two of the plastic clips and squeeze them with pliers to remove...less chance they will break.