Hello Geraldo,
As far as the bearings go, it all depends on what shape they are in. Do replace all seals. If the bearings appear to be in good shape then cleaning and repacking should be all that's needed. There have been discussions about how to remove brake drum/hubs, from backing off axle nut a few threads, reinserting cotter pin for safety and driving in circles or zig zags left and right until the hubs pop loose, to a detailed description on how to build a heavy duty hub puller that uses a bottle jack horizontally to apply the needed force safely and without damaging anything. It's always good to service bearings or at least inspect freshly serviced bearings while doing a brake service.
