you need a special socket either 4 prong or if early axle 6 prong, or you can use a punch and hammer, basically there is an inner hub nut, and an outer hub nut with a keyed washer inbetween. All of that must be removed to pull the hub off the spindle. The outer bearing will just fall out, so be careful.
If you remove the outer bearing, put the inner hub nut back on the spindle and then remove the hub assembly, the inner hub seal pops right off so you have access the the inner bearing without damaging the hub seal...