I use progressively finer wet-or-dry sandpaper until I get it down to 1500 or 2000 grit. I then use a buffing wheel setup I have. It's a swamp cooler motor bolted to a stand with an adapter from Eastwood and one their buffing wheels and compound. For no more than you are doing you could probably do the buffing by hand with a cloth and some fine auto polishing compound once you get the sandpaper part done.