Several options:

1. Thousands of them have been reinstalled with a 2 x 4 and a 5# hammer. Lots of folks will tell you never to hammer on a balancer, but read sentence one again. Hit on the hub - not on the edges.

2. Drill your crank for a bolt and pull it on.

3. Put it in your oven at 250* fir an hour or so, then use method 1.