Andrew's just mad that he can't figure out a good method to try, so I'll cut him some slack.
A way to do it might be to try cutting a circle with a plasma cutter. Then punch the middle out. The do'ers of this method will probably need gas masks for noxious fumes if it's a rare-earth magnet, as well as alot of other protective gear for the flying molten magnet. There are probably other issues I can't even imagine as well.
Good luck
