"To fix a Moen bathroom faucet handle, follow these steps:

Shut off the water supply to the faucet. Remove any decorative caps or handles to access the retaining screw. Use a screwdriver or Allen wrench to loosen and remove the retaining screw. Gently pull the handle off the faucet body, exposing the cartridge or valve mechanism. Inspect the handle and cartridge for any damage or worn-out parts. Replace any faulty components, such as O-rings or the cartridge, with Moen-specific replacement parts. Reassemble the faucet, ensuring all components are properly aligned and tightened. Turn on the water supply and test the faucet for leaks or proper operation."