If you're saavy, you can attempt to repair a leaky shower faucet. To start, you'll want to turn off your water supply to the shower. Next, remove the faucet handle and keep any small parts like screws in a safe place while working. Now you can identify the source of the leak, (which is usually the washer or the O-ring.) Remove the washer or O-ring and replace it and then reassemble the faucet. When finished, turn the water supply back on. If the leaky faucet is more complex, (e.g. there is a leak in the valve), you'll want to contact your local plumber for help. More information about how to fix plumbing leaks.