How can I remove or replace a faucet aerator using a faucet aerator key?

To remove or replace a faucet aerator using a faucet aerator key, first, locate the aerator at the tip of the faucet. Insert the key into the aerator and turn it counterclockwise to unscrew it. Once removed, you can either clean or replace the aerator before screwing it back on by turning it clockwise.