It's pretty much the same as a mutli-speed. You unthread the little retainer (clockwise), pull a few shims, and walla! All the 1/8" bearings run for their life across your bench! If you're lucky, the 3-4 pawls that are in there (held in by nice, tiny little springs, will jump out and flee too! :mrgreen:
I have pulled them apart before to make spinner necklaces with freewheels. It's a pain to get them back together though.