It isn't very difficult to do... however, I highly recommend taking a box and cutting a hole in the bottom of it, just big enough for the winch to fit through, and putting it over the winch before you start working on it. It will, hopefully, catch any parts that try to escape. 
There is not much that you can not get shipped to you if you can not get locally.
I usually try the local guys first and if that does not work i get it shipped to me from the internet.
I have never taken apart a winch to grease but thinking maybe its a good idea to learn with my 2007 H-36,any suggestions on a good book,I do have the paper work from Lewmar but would like more.
nick
Nick