To remove the axle shafts you remove both rear wheels, disconnect the back end of the brake rods going to the pedals, remove all the nuts in the axle housing flange just behind the brake backing plate and pull the axle out. The large brake rod that comes out of the backing place and over to the center housing is just sitting in a socket so it will pull right out. This is a heavy assembly with all the brakes still assembled. Be careful pulling the axle out as it is going through the inner seal, although I would probably replace those seals while the axle is out if they are old.
You should find shims at the end of the axle where it bolts to the flange. The shims set axle end clearance where they meet in the differential. You might get away with just putting the shims back the way they where, but I would go through the procedure in the service book on setting the axle end play to be safe.