It is often convenient to retrofit an old-fashioned bathtub into a new shower-and-bath combination. Changing the fixtures to accommodate a simple new shower diverter and showerhead wand is not difficult and less expensive than replacing the entire bathtub unit. Many different styles and finishes of bathtub shower diverters with "handheld" shower wands, as well as various styles of shower curtains and curtain rings, are available at home improvement stores.
Determine where you want to install your new showerhead "wand." Stand in the tub and mark a comfortable height so the water will not stream directly into the eyes. Measure the distance from this mark down to the location of the bathtub faucet to determine the needed length of the shower wand hose.
Purchase a new faucet spigot, one that has a shower diverter built in and a threaded connection for the showerhead supply hose. Purchase a showerhead kit that will fit on the spigot connector and that is long enough to reach where the showerhead will be located in the wall bracket. Purchase a shower curtain "ring" or curtain rod to fit the size of the tub or opening.
Place the showerhead wand in the supplied wall bracket, without the hose attached. Mark where to install the wall bracket so the showerhead will be positioned correctly. Install the wall bracket using supplied screws and wall anchors. If drilling into porcelain tile, use a special tile drill bit and drill very slowly to prevent cracking the tile.
Turn off the hot and cold water supply to the bathtub faucets. Unscrew the faucet spigot from the bathtub spigot pipe. Do not use too much force and avoid stripping the threads of the faucet pipe. Clean the exposed threaded pipe and apply two or three layers of plumber's tape around the threaded part of the stem.
Screw the new faucet spigot with the diverter onto the pipe stem. Make sure the faucet ends up in the correct position to fill the tub. Attach the showerhead hose to the connector, and use plumber's tape on the threaded nipple. Turn on the cold water supply and test the new showerhead. Look for any drips or leaks from connections. Turn off the cold water supply and seal any leaks with more plumber's tape and tighter threading if necessary.
Install a shower curtain rod. You'll need a three- or four-sided "ring" if the walls around your tub are not covered with waterproof tiles or plastic panels. Install the ring around the perimeter of the bathtub; it will usually be suspended from the ceiling. The ring should be located directly above the inner edge of the tub. If three of the walls are already waterproof, you will only need an ordinary shower curtain rod held in place with tension springs.
Turn on the hot and cold water supply and test the shower and curtain system as if in real use. Adjust the showerhead wand handle up or down in the wall bracket if necessary.
If it is necessary to change the tap handles, make sure you place the hot water handle to the left of the spigot and the cold water handle to the right, to prevent accidental scalding.