This is where I learned how to restuff electrolytic cans.
http://www.picturetrail.com/sfx/album/view/22501148
It is in a sticky on the tech forum here. I'm still working on getting the crimp to look original when I'm done. Although you can't see that part of the job after you mount the can, I still like it to look as untouched as I can. My best advice is to work the crimp section off of the can as slowly and deliberately as you can. The cleaner you can get that to straighten out, the cleaner it will be to "re-crimp" it back into place.