If your replacement faucet is not the right size, pick up a connector and fitting from the hardware store. You will also need wrenches. First turn off the water supply. Then, brace the pipe with a pipe wrench. Use another wrench as a lever and remove the faucet. Take a piece of plumber's tape and wrap the brass connector. Make sure you thread the tape in the same direction that you screw on the connector. Screw the connector on by hand and tighten it with a wrench. Use the other wrench to keep the pipe steady. Wrap the other side of the connector in plumber's tape and attach the size reducer nut fitting. To finish the project, add the replacement faucet to the nut fitting.