Originally Posted by WizardOfBoz

Anklework's point, that if the fork tube is distorted you may need more expert help, is a good one. If you can't get the race off with penetrant, heat, and force, then you have to consider alternate methods. Typically a bearing race is harder and stronger than the steer tube, and hence if overtightened its the tube, not the race, that is distorted. So this may involve cutting the fork steer tube (like with an abrasive disc in a small hand-held rotary tool). Not such a bad thing if the models was common - ebay will have spares. But if the bike is rare, and worthy, you may end up having a new steerer welded or (with sleeves) brazed on

I suspect that with diligence, heat, penetrant, working the thing back and forth, and having the fork braced well, you should be able to get it off.