There are several types of body showers on many price levels. Choose one that will fit your budget and existing shower.
To ensure there's room to install the body shower, take off the cover plate to expose the valve body and the water lines. Shut off the water at the main using a curb key. Close the valves at the water heater, and turn off the power to the water heater.
Remove the shower arm using slip-joint pliers to loosen it first. Remove any parts you can from the valve body (Image 1). Use a hacksaw to cut the water line, leaving as much copper pipe as possible above the valve body (Image 2), then cut either the hot or cold line.
Before installing the anchors, place a piece of painter's tape over the spot where the hole will be drilled. This helps prevent damage to the tile. Using a drill with a tile bit, drill the hole into the tile.
Apply silicone caulk to the anchor for a good seal. Follow the manufacturer's instructions when installing anchors. Place the anchor into the hole, then set the screw.
Attach the stainless steel water line to the adapters installed earlier, then tighten with pliers (Image 1). Mount the body shower by lining up the bolts over the keyholes on the back of the unit. Start with the top and work your way to the bottom (Image 2).
Place the shower arm into the holder, and attach the hose to the male adapter on the unit. Connect the water lines to the female adapter on the back of the cover plate. Put the cover plate on, then snap on the decorative plates around the jets.
Turn on the water at the main, then turn on the water and power to the water heater. Turn on the shower and allow the water to cycle through, then test the temperature to ensure the anti-scald valve is working properly. Finally, install the handle and tighten the setscrew.