I'm in a rental homne that was built in 1975, I think. The shower faucet is leaking. This is the kind where you have different knob for the cold water on your right and another for the hot water on your left, and the faucet is in the center. I tried unscrewing the left knob but doesn't know where or how to change the "gasket"? I'm not even sure if that's the correct word for it.
Please help.
Thanks much.