Tools are quite basic and not to expensive. All you need are the items below:
1) Dremel (I use the cordless version) however any one will do.
2) Felt polishing tip/wheel and the bit that holds the tip/wheel.
http://www.toolbarn.com/images/dremel/422.jpg
http://www.toolbarn.com/images/dremel/429.jpg
http://www.toolbarn.com/images/dremel/401.jpg
3) Flitz metal polish, you don't need a fine abrasive will just take a tad longer if you use flitz by itself.
4) Just apply the metal polish to the part, spread it around with the wheel and then turn it on (low speed). Simply move the head around until you see the finish coming off and buff to desired sheen. Really can't screw it up.
5) I use isopropyl alcohol to clean off parts and threads.
Pretty much any hobby store will carry the dremel and heads, also a good place to look is at your local home depot or large hardwares store. For bare metal it actually keeps very well, I ocosanlly wipe it off with my shirt, the flitz really seems to help against corosion. I have polished up other lights and even gun barrels to (bare metel) and have had no problems with corrosion.