How do I fix a leaking kitchen-sink faucet spout?
If the faucet spout is dripping from the aerator, you need to
repair the faucet stem or cartridge. If there is water coming out around the base of the faucet;
a. Unscrew the faucet spout’s mounting nut on top of the faucet.
b. Lift the spout out of the faucet.
c. Take the spout to your hardware store to find a replacement O- ring.
d. Lubricate the O-ring with plumber’s grease.
e. Reinstall the faucet spout and check for leaks.