Dear Bill;
Use the puller that connects to the gear with (2 3/8 #6) bolts/washers.
Using a 6Pt socket on the puller, tighten it to around 100#+/-. If it has not 'broken loose'; strike the puller shaft with a large hammer in a direction toward the gear. Now add some torque to the puller via the socket. Repeat this till it comes off.
That's how, but can be avoided like Bob explained.
A new seal is a good idea as well.
Good luck.
