Hi! My Water Heater is starting to leak a little. The Tech came and said they can replace it, but the PVC vent material is not up to code and by law must be replaced first (or at the same time). Their price for that is not so cheap. So I'm thinking of doing it myself. I think I need the System 636 Pipe (white) and need to remove ABS (black). Is it OK to cut this with a table saw? Do I need to use 636 primer before the cement? What's the best way to disconnect the old pieces? As I should be able to use the old pieces to get the exact same new piece sizes.