I have 4 wheel drums and am wanting to change the original wheel studs. Can this be done on the car or do I have to pull the axles? What is the easiest way to do this?

Light press fit with splines hold them in. Knock them out with a hammer, use a lug nut and several oiled up washers to install the new ones making sure the head is up tight against the axle flange. Hardest part might be getting the drums off.