Unless you need to service the bushes or change the cam, the engine will come apart without the need to remove the cam gear. Otherwise a drilled flat bar and a couple of bolts to suit the tapped holes in the gear and the usual precautions to protect the camshaft thread should pull the gear off. The hooligans' method is two tyre levers, or worse, against the crankcase. If you are tempted to use this method, warm the gear with a hot air gun. Even so, they usually come off fairly easily, not needing too much force. Otherwise separate the cases and gently tap the cam through the gear, protecting the cam threads as necessary. This is not good for the bush face, some would say.
Sure you are not confusing cranks and cams? The crankshaft pinion can be a variable, some quite loose, some murder tight. Before now I have resorted to homespun thin jaws ... the usual angle iron/ bolt/threaded rod/welder combination, plus a bit of gentle heat from the hot air gun. Don't be tempted to hammer the end of the crankshaft through the pinion..... it is relatively soft, and it is easy to bugger up the threads or bend the nose of the crankshaft.
Swarfy.