Warning to OP: if you remove the cartridge there might be a pin that gets removed. I always tie a string/thread to the pin while it is still in place and attach the other end of the string to the faucet/spigot so that if I accidentally drop the pin (since it is small), it doesn’t drop into the space behind the shower wall where I can never ever retrieve it. I’m sure there’s a way to get a new pin but you can’t turn the water back on until you do so the stakes are high!!