Turn off the water supply under the sink
Open the faucet to release any remaining water
Plug the sink drain to prevent losing small parts
Remove the faucet handle
Take out the cartridge, stem, or valve assembly
Inspect washers, O-rings, seals, and cartridges for wear or damage
Replace any damaged parts with matching new parts
Clean mineral buildup from faucet components
Reassemble the faucet
Turn the water supply back on
Test the faucet for leaks
Tighten connections if needed
Replace the entire faucet if repairs do not stop the leak