Step 3 · Remove Old Angle Stop
This is a critical step. Use two wrenches. Place one wrench on the valve body itself to hold it steady and prevent it from moving. Place the second wrench on the larger compression nut located at the back of the valve where it meets the copper pipe. Turn the compression nut counter-clockwise to loosen it. The first wrench's only job is to provide counter-torque so that the copper pipe in the wall does not twist. Once the nut is loose, unscrew it completely and slide the old valve off the pipe.