it can be done and ain't very hard. I'd recomend Superwinch hubs. The cost only a few bucks more than the standard Warn hubs, but have the quality of Warm premiums. Warn recomends some sort of conversion kit for it but I've heard of people not using them.
you can also try pulling out the auto hubs and cleaning them and regreasing them with a high quality grease. You'd be surprised how many hubs are repaced only cause the grease is dirty and gettin solid causing the hub to not work properly.
I work for a dealer and most the time the tech's will clean and regrease the hubs and they work fine.