Semiprofessional machine restorer here.
First off, this is not rocket science. Most of these methods suggested will work, but some also get a little carried away.
First off: Don't worry about using actual Scotchbrite, like green or maroon. First off, the grit is so comparatively fine, that it would take heroic effort, and probably a steam-driven elbow, to take a measurable amount of metal off.
Second, the rust has already damaged the surface- and even light surface rust will cause deeper divots than the Scotchbrite will.
After many attempts at using everything from wire wheels to Naval Jelly, the simplest route, in my opinion, is first, get a small razor blade holder, and a small pack of single-edge, and just push the bulk of the rust off like you're scraping frost off a windshield.
The blades dull rapidly, swap out for fresh as needed.
After the bulk is off, cut some Scotchbrite into small squares, and use some WD-40 (or your oil of choice) to scrub the new surface.
Again, the Scotchbrite wears out rapidly, replace as needed.
Wipe it clean, and you're pretty much done.
A light whetstone/oil stone also lubed with WD/whatever, lightly scuffed over the surface, will knock down any minor dings or tiny burrs from scratches.
That's really all you need.
Doc.
