PJ, The common way to remove the old gear when I was hanging out at local shops and stripped timing gears were very common was to: break off the old gear to expose the hub at the keyway, then with a sharp chisel cut in toward the key.The hub is soft and will split with just a few blows then you can easily remove it.I would have a helper with a second heavy hammer resting it opposite your cut to make the chisel more effective.
