Hubs arnt near as complicated as folks think at least not the ones on smaller trailers I don't know about the bass boat trailers with the high dollar hubs and stuff! Pull em off get a new seal and cotter pin clean out the old grease check the bearings and races make sure there is no scaring or damage re grease them and stick em back together! All you need is a pair of pliers to remove the cotter pin a pair of channel locks to get the spindle nut off and a hammer and punch if you need to replace the races!