I made a video of helpful tips for minimizing stress for chickens and making handling easier when you are doing things like removing spurs.
I've also posted pics of the Hot Potato Method on the PoultryPedia page Rooster Spurs.
When I've shortened spurs that way, the roosters didn't act like they experienced a large amount of pain when the outer shell was twisted off. There isn't a lot of skin connection between the spur shell and a leg. However, spurs are more vulnerable for a few weeks after shell removal.