A: Chris, the short answer is: You don't!

Compression fittings work with three components. The compression nut, ferrule, and fitting body. When you tighten the nut on to the body, the ferrule between the two components crimps around the pipe and that seals the fitting.

Usually the fitting nut and ferrule have to be cut off the pipe and the new pipe end can be used for the new connection. However, sometimes there may not be enough room on the pipe to cut out the fitting and that's where things will get tough. I

have had to open up walls and floors to get access to a good pipe end and then had to run some new lines. Hopefully, you will have room to work with this one. Remember, I never said plumbing was easy!