Step 3 · Remove the Old Angle Stop
Now you will remove the entire valve assembly. Place one adjustable wrench on the main body of the angle stop. Place a second adjustable wrench or pipe wrench on the pipe or nut behind it for counter-torque. This is crucial to avoid damaging the pipe in the wall. Hold the second wrench steady and use the first wrench to turn the compression nut on the angle stop counter-clockwise. It may require significant force to break it loose. Once it's loose, you should be able to unscrew the entire valve from the compression nut and slide it off the copper pipe.