I picked up a fixer-upper Gary Fisher MTB for no very good reason. While attempting to adjust the headset, I found that tightening the adjustment bolt did not take up any play. After a few turns, I found the star nut to be completely stripped. I'm tempted to believe this was a preexisting condition, rather than my own incompetence, as the previous owner was clearly a mechanical nitwit (there are a few other things seriously under/overtightened on the bike).
What's the best way to remove the dead star nut? I suppose I could just pound it out with a mallet and dowel rod, but won't that gall the fork steerer excessively?