I have damaged one while trying to remove it.
I use a pin punch, its stainless steel, picked it up of the ground at the scrap yard.
Through the fins on the flywheel, tapping on the body of the housing.
Its a good idea to take the tin plate of and all the balls and stuff out. Clean all that stuff up before you put it back together.
Thanks for the link to the pics grumpy. I might have a go at making something up.