I've been starting my helis using my trust drill. But, I have a Torqmaster 90 left over from my plank days. I was going to bolt a KSJ on there. Does anyone know how to remove that damn rubber doughnut thing off the output shaft, so i can clamp my KSJ there?

pull the rubber part out, it just slips in. After you get it out, you can remove the nut that holds the metal "cup" on.