Replace A Bathroom Faucet - A Woman S Guide To Installing A Faucet Sand And Sisal : Securing each component of the faucet (the handles and the faucet itself) will be a nut of some sort on the underside of the countertop, replace the mounting plate (bumps toward the countertop so as to improve you've just upgraded your bathroom vanity faucet, and it functions well and looks amazing.