If you want to change your shower head, first you have to remove the shower head already in place. This is not a complicated project, and it only takes about ten minutes. All it requires is a wrench and some special plumber’s tape, commonly called Teflon(r) tape.
Place a towel inside the tub or on the shower floor so you have something to stand on and do not damage the surface.
Unscrew the nut behind the shower head with a wrench. It helps to hold the shower head as you turn the nut so the entire shower head does not turn. You only want the nut to turn.
Pull the shower head off. Remove all the tape around the threads of the pipe. Wrap the threads with new tape, use at least 3 wraps and completely cover all the threads.
Thread the nut for the new shower head onto the pipe. Tighten the nut with the wrench until it is very tight, but do not over tighten it. This may damage the threads.
If you want to clean the shower head, remove it and soak it in a lime and calcium deposit cleaner. This removes all the deposits and restores the finish. Replacing the shower head will also improve water pressure if the old unit is clogged beyond repair.