I have seen some of these wheel bearing repacking videos and would like to comment. As shown on these videos, the attention to keeping grease away from braking surfaces is not sufficient from my perspective. It truly doesn’t take much grease to contaminate frictional material and cleaning it is practically impossible. Most of the frictional materials are porous enough to soak up grease quickly. Using solvent to clean porous material just drives grease in deeper. Metal can be clean but I did not notice cleaning the inner surface of the drum before the final assembly. So, from my perspective, keep your grease fingers away from braking surfaces.