This discussion should probably be over in the Gunsmith Forurm, but pressing on... I've used commercially made tools from a couple of distributors, a custom-made one by revolversmith Fred Schmidt, and a #0 Phillips head Craftsman screw driver to deal with removing and replacing the rebound spring, but truth to tell (although I probably have more thumbs and fewer fingers than I should ) I've never noticed any particular need for any specific or special tool to do this task.

Froggie