The first step is to shut off the water supply to your faucet. The next step is to remove the index button on your handle, screw, and then the handle should come off. Note how the cartridge is in place, direction, etc. Then remove the cartridge and place the new cartridge the exact same way as the other one was positioned. Replace the handle components and turn the water on to test to make sure that everything is working properly. If you have any problems, please call Customer Service at 800-888-4458.