Flywheel Fun...

If you don't have a lathe in your garage, a D.A. with a Scotchbrite pad and plenty of brake cleaner is about your only option at 11 pm on Thanksgiving eve... or like Rusty said, just run it as is. Hell, it's an Amigo, fer cryin' out loud... :)
And you're better off, and safer too, just leaving it rather than trying to hand grind it. You really don't want to remove ANY material, just dress the surface or you'll be headed to chatter city.