the easiest way is to buy a bench grinder, b+q do 1 for about £20 and buy a polishing kit which is 2 or 3 different mops and soaps with a mandrel to convert 1 end . i have had 1 for years and have done loads of bike bits , heels swing arms footpegs etc, you can use smaller, mops and shapes to get into difficult bits, its not that hard and loads better than by hand.