The absolute best cotter removal tool I have ever used is a pneumatic chisel with a punch bit in it. The combination of the vibration and the impact force loosened every pin with no pin deformation that I have use it on. And this experience was back in the late 1970s when pinned cranks were far more common then today. I have used the Var Constricteur press (which sucks), the two versions of the Park press (the cast and the folded and welded ones, which work fairly well), the Var brass hammer, many different punches and hammers (punch held in vice grip, thank you). And the pneumatic tool beats them all by far. Andy.