There are two good ways to remove Side Rails from a game, and the way you choose depends on the finish of the rails.
Rails with their natural "brushed stainless" finish are the easiest, because we can remove any tiny scratches that occur during removal with fine sandpaper.
Rails with Powdercoat, Brass or Chrome Plating are quite fragile, and require much more care.
Let's start with Stainless, as that is what you will encounter 99% of the time.