I have a one knob delta faucet in my bathtub, and it is dripping from the spout. I would like to know how to fix this problem step-by-step. My brother told me that I need to first turn off the main water line that leads to the house. But I do not know where it is located. Please, if someone can help me fix this problem, I will be very grateful. Thanks.

Call A Repair Plumber.