Cut the PVC pipe into four even pieces with are two feet long each. Use the measuring tape and the pencil to mark the pipe. Use the pipe cutter or saw to make the cuts.
Determine how much higher you want the table to be. Measure that distance from one end of one of each pipe section. Make a mark at that location. This location should be no more than of one-third the length of the pipe.
Drill a hole through the pipe at that mark. Place a bolt through the holes on both sides of the pipe. Screw the nut into the bolt.
Repeat this for all other pieces of pipe, measuring the height difference, drilling and securing the bolt.
Place the extenders onto the table legs so that the legs are inside of the pipe and are resting on the bolts.