MIKE , here's my low-tech way of doing it. you'll need some fine sand paper#800 or 1000 grit. some very fine steel wool (xx or xxx fine) . i use wenol or mothers polish. i prefer wenol in the blue tube(vs orange) it doesn't have a lot of grit in it.
i start by wiping the wenol on the part with my finger. get the piece covered well, then with the xxx steel wool start cleaning it in gentle circles. wipe with a soft cloth. the black residue should come off. then wipe again with another clean cloth.
if you have any major scratches i use the wenol and the sand paper. and lightly buff the scratch out . then polish as above.
or i cheat and take it to work and use our industrial buffer and rouge. i'm sure there are many other ways,but this works for me .
robin