I think you're probably right. My thought was to try some penetrating oil and a pickle fork (one page up is a list of tools needed:
Tools
General mechanic’s tool kit:
automotive (Appendix B, Item 1)
Pickle fork (Appendix B, Item 129)
Special Tools
Socket adapter (Appendix B, Item 146)
Crowfoot 15/16 in. (Appendix B, Item 151)
or (lastly) pull the shaft and geared hub, put a gear/pulley puller on it after judicious application of heat, Kroil, PB Blaster and/or Schaefer's. But beating it will certainly teach it a lesson it won't soon forget.
[man I hope I don't have to change those parts anytime soon]