Turn off the water supply under the sink
Open the faucet handle
Remove the handle screw and handle
Take out the decorative cap or trim if present
Remove the retaining nut or cartridge clip
Pull out the cartridge, stem, or valve assembly
Inspect washers, O-rings, and seals for wear or damage
Replace worn washers, O-rings, seals, or the cartridge
Clean mineral buildup from faucet parts
Reassemble the faucet in reverse order
Turn the water supply back on
Test the faucet for leaks
Tighten connections if dripping continues
Replace the entire faucet if repairs do not stop the drip