If you are removing it by yourself, with the camper lowered as far as possible, I used two 12' 2x4 side by side laid against the top edge of the roof to hold it off the camper.
Sat the AC on some card board and tied a rope around it.
With the wife holding the 2x4s against the camper, I held the rope and slide the AC on the card board over the side and onto the 2x4s, then, holding back with the rope, let it slide down the 2x4s.
Put it back up there the same way.
Have done that twice. Works well. Second time, I tacked two horizontal pieces to keep the 2x4s together. Could probably use a ladder to do the same.
Joe and Evelyn