I use a very strong chemical paint remover (it has to soak in about 20 minutes) and then I use a paint strip tool or anything thats flat and sharp to scrape of most of the paint and then I start sanding away the last bits of paint with a grid 150 or smoother.
mine are in this thread:
http://www.germanlook.com/Forums/sho...?t=5793&page=2
I keep sanding the surface smoother and smoother from a grid 220 up til a grid 2000(wet), where I can I use a small excentric electrical sander and the rest is done manually (takes a long time and do not forget to put some tape around your fingers to protect them).