Put the rear of the car on stands and remove the wheel from the desired side.
Remove the hub cap, unlock and unscrew the nut securing the hub to the trunnion.
Remove the brake drum or disc. Remove the thrust washer and bearing inner races.
Place the brake drum or disc on a workbench and press the roller bearing outer races out of the hub using a bronze drift.
Press the new bearing outer races into the hub using drifts of the appropriate diameter.
In the future, perform operations in the reverse order of removal, while adjusting the preload of the hub bearings.