I don't even want to think about it. Got new rear tires for the BMW a few weeks back. Tried doing it on a machine, but even then it didn't work. Low profile tires are evil. Had to end up having a tech do it with a special machine.
Speaking of removing tires manually.... I've done it many times, but on this old truck of mine, I'm having a helluva time just getting the bead to break loose. I think I'll be taking the wheels to the shop just to have the tires removed. D'oh.