Determine the type of faucet you have. There are four main types, and each is taken apart differently: ball, cartridge, compression and disc. A single-handle faucet is usually a ball, cartridge or disc faucet. A kitchen sink with two controls is a compression faucet.
Differentiate between the faucets. A ball faucet rotates with a single lever on a slotted metal ball. A cartridge faucet contains a metal or plastic cartridge. A disc faucet allows the faucet to move side to side, to be lifted and lowered. If you're unable to determine the type of faucet, make a note of the brand and model and call your local hardware store.
Locate the water shutoff valve underneath the sink and turn it to shut it off; you can usually do this by hand.
Locate the screws. These should be located underneath the caps of the faucet handles. Pry up the caps with a flat screwdriver. If you do not have capped faucet handles, look for the screws in the handle or handles.
Take apart a ball faucet by removing the cap and screw, then pulling off the handle. Locate the ball, seals and springs. Take note of how the springs are installed; you'll need to replace them in the exact same order. Use tweezers to remove the springs and valve seats, then twist and lift the spout. Locate the O-ring and remove it from the housing (replace it if the sink leaks). Also replace the valve seals, springs and ball; install the components exactly as you disassembled them.
Take apart a cartridge faucet by removing the cap and unscrewing the screw on the handle. Remove the handle by lifting it up, the nut by using pliers and then the spout by lifting it up. Locate the retaining clip and pull it out with pliers. Locate the O-ring and remove it. Remove the cartridge by pulling it upward with pliers. Replace if necessary. Reattach all components exactly as you disassembled them.
Take apart a compression faucet by removing the cap and screw. Lift and remove the handle, and unscrew the nut from the faucet. Using pliers, unscrew the stem; remove the screw holding the washer. Remove the washer (replace it if your sink leaks). Also replace the stem and O-ring if there are leaks.
To take apart a disk faucet, lift the handle, find the screw and remove it. Remove the handle and the housing. Locate the disk cartridge and remove the screws, then lift the disk out. Replace the disk if it's cracked. Clean and rinse the cylinder opening, and install new seals if necessary. Reinstall all components exactly as you disassembled them.