Disconnect the supply tubes. These are the tubes that connect the faucet to the water supply. Use the adjustable wrench to loosen the nuts where the hoses attach to the water supply. Use the basin wrench to loosen the nut attaching the hoses to the faucet. Turn the nuts to the left (counterclockwise) to loosen them. Once you’ve loosened the nuts with the wrenches, you can remove them the rest of the way by hand. Wipe up any water that drips onto the bottom of the vanity immediately to prevent damage or warping.
Loosen the lock nuts to take out the old faucet. Most faucets are attached to the sink by locknuts attached to the tailpieces under the sink. Use your hands or an adjustable wrench to loosen the nuts and unthread them from the tailpieces. Turn them to the left (counterclockwise) to loosen them. Remove the nuts and the washers from the tailpieces. Once you’ve removed the supply lines, nuts, and washers, the faucet will be loose. Hold the faucet in both hands and pull it straight out from the mounting holes. Remove the gasket if there is one and set it aside with the faucet. Use the flashlight to locate the nuts under the sink if you’re having trouble locating them.
Scrub the faucet holes. With a sponge or gentle abrasive pad, scrub the mounting holes around the sink where the faucet sits. Use soap and water or your favorite cleaner or detergent. Once the area is clean, rinse it well, pat it dry, and let it air dry completely. To remove old sealant or silicone, dampen a sponge or rag with mineral spirits and wipe the area clean. Then rinse the area with clean water and pat it dry.
Determine what kind of faucet you have. Once you’ve removed the old faucet from the mounting holes, you can figure out what hole configuration you’re working with and the type of faucet you need. There are three major types of faucets:
Single hole, where the sink will only have one hole for the faucet, and the faucet will all be one simple piece with a single handle. Center-set, where there will be three holes in the sink and the one-piece faucet will have separate handles controlling the hot and cold water. Widespread or split-set, which work with three-hole basins, but the spout and two handles come in three separate pieces.
Purchase a new faucet. Before you go to the home or hardware store for a new faucet, determine the type of faucet you have, look at your basin hole configuration, and measure the distance between the holes so that you get the right replacement faucet. Write down the number of holes your basin has, the type of faucet that was on there, and the distance between the holes. If you want to replace your old faucet with a new kind, you’ll have to replace the basin as well.