I have an old e-motor that I pulled out of an old style kid's electric car. You know, one of those cars that little kids can drive around in your yard. I have no idea what they are called. Any way, this motor is probably 5-10 years old and has spent most of its time outside. The outside of the motor is all rusted up but from what I can see, the inside still looks nice with no rust. Any ideas/suggestions on how to remove the rust?