To open a septic tank system, first find the system by following the direction of the drain at least 10 feet away from the foundation of the house. Dig the soil away from the top of the tank, and locate an 18-inch square piece of concrete in the middle of the tank.
Sweep away any dirt from the lid and create a slant on each side of the opening to divert the debris. Wedge a screwdriver into the seam of the lid and start working it loose. Once it's loose enough, insert a prybar into the seam and lift up the lid; you may need to ask another person to help you lift the lid off of the tank, as it is very heavy. Take every precaution to keep the lid in one piece without any chips or cracks.
After removing the lid, you can pump and repair the tank. Do not let any debris enter the open tank. Never enter the septic tank, as doing so can cause suffocation or death. When replacing the lid, ensure the seal between the lid and tank is tight.
Once the repair is complete, backfill the hole and mark its location. Use a stepping stone or landmark that is level with the ground for any future repairs.