[header] How to replace a bathroom faucet handle [title] Turn off the water supply to the faucet. [step] Look beneath the sink for a valve close to the wall on the same side as the handle you are replacing. If this is a single handle faucet, turn off both supplies. 
When you locate them, twist the water supply valve or valves tightly to the right. [title] Test the faucet to ensure no water comes out when the handle to be replaced is turned.