Here are the steps to fix a leaky faucet:

1. Turn off the water supply valves underneath the sink.
2. Remove the faucet handle by pushing it back to access the set screw, removing the screw, and lifting off the handle.
3. Remove the escutcheon cap and cylinder, and lift out the neoprene seals from the cylinder.
4. If the seals are damaged, replace them.
5. Clean the cylinder openings with distilled white vinegar and a soft scouring pad, then rinse them thoroughly.
6. Reassemble the faucet and turn on the water to check for leaks.
7. If water leaks from around the ball stem, use the spanner tool to tighten the adjusting ring until the leak stops.
8. Finally, replace the faucet handle.

I hope this helps! Let me know if you have any other questions or if there's anything else I can help you with.