were is it located can you get a drill in there ?
if so you can bye a drill bit witch drills in to the part then you chuck the drill in reverce and the drill bit catches on the peace you are trying to get out and unscrews it
i know because when i was a kid i snaped the pedal off the crank of my push bike and dad baught one of those tools and he got it out instanty
if you can get a drill in there ill ask the old man what thay are called let me know