Lay out the location for the new sprinkler line. Determine which line needs to move and where the new line needs to go. Measure and draw a diagram.
Turn the water to the system off.
Dig a trench to remove the old line and a trench for the new line. Be sure the location and length of the line will provide enough pressure in the new location. Avoid 90-degree turns as much as possible when moving a sprinkler line.
Cut the old pipe where it needs to be moved using a hacksaw or PVC cutters. Place caps on any ends that will no longer be connected to the sprinkler system. Clean the end thoroughly with a rag first, then install the cap with PVC cement and allow it to dry completely.
Install the new pipe and fixtures using PVC cement. Consider using telescoping repair fittings for easier rerouting. Be sure to apply cement, put the pieces together, then the rotate pipe 1/4 of a turn and hold in place for 10 seconds to prevent the joints from falling apart.
Install any new sprinkler heads in the correct position, if needed.
Allow the joints to dry completely, then test the system. If there are leaks, repair and re-test. When there are no leaks and the sprinklers cover the ground correctly, fill the trenches in with dirt. Add seed or sod to the dirt over the trenches.