Step 1 · Shut Off Water Supply and Prepare Work Area

The first and most critical step is to prevent water from flowing to the faucet while you work. Locate the two shutoff valves under the sink, one for hot water and one for cold. Turn the handles clockwise until they are fully closed. If there are no shutoff valves under the sink, you will need to turn off the main water supply to the entire house. After closing the valves, turn the faucet handle to the 'on' position in the middle (mixed hot/cold) to relieve any residual water pressure and confirm that the water is indeed off. Place a towel in the sink basin over the drain to catch any small parts.