Remove the handle screw with a Phillips head screwdriver. The handle screw holds the handle to the faucet's stem and is located in the center of the handle.
Pull the handle away from the shower's wall to remove it from the faucet.
Remove the escutcheon plate that rests against the shower wall behind the faucet's handle. The escutcheon plate is used to prevent water from entering the wall when the shower is in use. To remove the plate, first remove the screw(s) from the face of the plate with a Phillips head screwdriver, then pull the plate away from the wall. Stubborn plates may be pried away from the wall with a flathead screwdriver.
Turn off the faucet's water supply at the shutoff valves. The shutoff valves are revealed behind the escutcheon plate. There is one valve on either side of the faucet. One valve controls the hot water, and the other controls the cold water. Turn the large screw located in the center of each valve in a clockwise direction with a large flathead screwdriver to turn off the water.
Unscrew and remove the single bonnet nut located in the center of the faucet by turning the bonnet nut in a counterclockwise direction with an adjustable wrench.
Grasp the tip of the faucet valve with a pair of pliers; then pull the faucet out of the wall.
Insert the replacement faucet into the wall; then install and tighten the single bonnet nut over the faucet.
Turn each water supply valve on by turning the valve in a counterclockwise direction with a flathead screwdriver.
Position the escutcheon plate over the faucet assembly; then insert and tighten the plate's screw(s).
Slide the faucet's handle onto the faucet; then insert and tighten the handle's single retaining screw with a Phillips head screwdriver to complete the installation.