Glue one end of the 15-foot PVC pipe into the center opening of the PVC T-joint.
Glue one end of one 8-inch PVC pipe into the left opening of the T-joint. Repeat with the other pipe in the right opening of the T-joint. Allow the PVC glue to dry about 15 minutes.
Hold the plywood upright, and hold the crosspiece, not the long handle, of the PVC tool up next to it. Maneuver the crosspiece so that it rests along the top of the plywood, about a half inch from the top edge.
Drill the wood screws in through the plywood and into the PVC pipe. Start in the middle and work your way out toward each end, placing screws about one inch apart.
Try to pry the plywood from the crosspiece. Add screws to any areas that are loose or do not sit flush with the crosspiece.