While it's good to have the plumber's number handy for emergencies, most people are quite capable of fixing simple problems like a clogged or leaky faucet. One of the more uncertain steps in do-it-yourself plumbing is disassembling the components. To remove mineral deposits or replace an old washer in a leaky shower, you will have to disassemble the shower head. As long as you keep all the shower head parts contained in one place, you can complete these repairs without a plumber.
Turn off the water supply. You may have a valve that supplies water directly to the shower/bathtub, or you may have to shut off the main water line to the house.
Locate the shower head's collar nut, which attaches to the arm, the pipe that protrudes from the wall. Wrap the nut in a rag or other protective layer so you don't scratch the finish. Loosen the collar nut with a wrench or pliers.
Unscrew the swivel ball nut that holds the shower head to the mounting collar, using a wrench. Once this piece is removed, the parts will come apart fairly easily. Take note of how they go together for reassembly.