Wheel Cylinder

Fig. 1: Remove the brake shoes and the brake line, then remove the bolts and tilt the cylinder inwards . . .

Fig. 2: . . . then lift it up and off of the backing plate

Raise and support the rear end on jackstands.
Remove the brake drum and shoes.
Disconnect and plug the brake line(s) at the wheel cylinder.
Remove the attaching nuts from behind the backing plate and remove the wheel cylinder.
Installation is the reverse of removal.