Things like pawls and pawl springs are still available at many marine
chandleries (West Marine
I sacrifice a plastic dish pan and cut a hole in the bottom just a little larger than the base of the winch
. Put the dish pan over the winch
before disassembly, the pan can catch errant pieces that I don't manage to keep my hands on. The pawls and springs are the most likely to go astray and easiest to replace, what you don't want to lose is any of the other parts that are harder to obtain.
and re-assembly is really pretty straightforward, no special tools required. We do ours every year or two and they are still going strong. On a couple of the winches you can't get the last gear
out without removing from the deck
, so we don't do that as often, but for the most part they can be completely disassembled from the top down.