reinstall...??? Good question. Here's my plan:
bake the gear in the oven at 300-350 for 15 mins. Leave the cam outdoors for a while (because the temps here in Georgia will be in the 30s all day today and tomorrow - believe it or not). Then put the woodruff key in place, remove the gear from the oven and it should drop in place.
I don't think getting it on will be nearly as difficult as getting it off. If I weren't so skeptical about gearing angles, noise and such I'd just buy a new cam gear and be done with it.
Then again the experience gained in using the puller could be helpful for future sake.