Polyvinyl chloride (PVC) glue or cement is a two-part solvent that is applied onto open joints of PVC runs to create permanent connections. The chemicals in the glue cause the PVC pipe that it is applied on to soften and then fuse together as the glue dries. This makes the PVC pipe joint even stronger than the rest of pipe because it is literally a single piece of pipe that has been doubled in thickness. The only way to take these connections apart is to cut them.
Cut off the supply running through the pipe that you need to cut. Allow the contents of the pipe to drain out before taking the joint apart.
Mark the PVC pipe with a marker on either side of the pipe where you want to open the joint. Use a clear, visible color so that you can see the mark while cutting.
Hold the blade of the saw against the first mark on the PVC pipe and allow the blade to cut into the pipe. Work the saw all the way through the pipe until you have made a complete cut through the first mark.
Cut into the second mark on the PVC pipe in the same way you did for the first mark. Have a friend hold the pipe steady while you make the second cut so that you can easily follow the marked line.
Pull out the cut joint of the PVC pipe and file the edges so that they are smooth. Filing will remove all of the burrs created by the saw.