/diy/ - Do It Yourself

I asked in the machinist thread bit let me try here too:
I have some aluminum hub rings for a truck that came to me the exact same size on the outside diameter as the wheel they go into. They won't go in. I need to shave off about .1 mm from the outside diameter. Is there a way I can do this myself while keeping the OD both perfectly round and keep the center the same.

Pic rel. It's just the flat surface on the outside that needs to get shaved down a tiny bit. I think sandpaper will do it easily but how do I keep it concentric.

So far my best idea is to put a round rod in a vice, pinch the inside of the ring up against it using a soft round thing in a power drill so it will spin the ring and then press some sandpaper against it close to where it's being pinched. Kind of hard to explain but maybe you catch my drift.