Preparations for the Move

• Examine the floor, and determine the shortest route from the old drain location to the new drain location. Draw this path in red crayon so that you can see it easily. Prepare yourself and the room for the task of moving the drain. Close all exterior doors, open the bathroom window and turn on the exhaust fan. Put on your safety goggles and face mask to protect yourself from dust.
  
  

Cutting out Your Path

• Use a side grinder with a a 4-inch concrete-cutting blade to cut the path from the old drain to the new drain. Follow the crayon lines you drew earlier. When you have cut through the surface of the concrete, use an electric chipping hammer to chip away the concrete between the lines. Start at one corner of the path, and keep working until you reach the dirt under the concrete. Remove the concrete, and throw it away.
  
  

Redoing the Plumbing

• Dig a trench in the dirt underneath the concrete. The trench must be the same depth as the original drain line. Save the dirt you dig up. Once you have built a trench, you can begin moving the pipe. Use a reciprocating saw to cut the old drain pipe horizontally at least 3 inches from the joint turning the drain upward. Put the cut-off piece into the trench, and aim it toward the old drain line. Measure the distance between this piece and the rest of the pipe, and mark a new piece of pipe with these measurements. Cut the new pipe. Glue a coupling onto the old pipe, and glue the new pipe onto the old pipe and the cut-off in the trench.
  
  

Finishing the Job

• Pack dirt under the new pipe until a bubble level shows that the slope is no greater than 1/4 inch per foot. Put the rest of the dirt on top of the pipe. Mix concrete and water according to manufacturers' instructions, and put a layer of concrete over the pipes with a trowel. Wait for the concrete to dry before walking on it.