The proper procedure requires you to thoroughly clean the bearings with mineral spirits or acetone. All traces of the old grease need to be eliminated.

Then, you start with clean hands and pack as much grease as you possibly can between the rollers. It takes about 6-7 minutes per bearing to properly accomplish this...........a process that is usually foreshortened by most mechanics. Additional grease is put into the raceway and hub for insurance, but the critical point of the grease is only where the rollers contact the raceways.