Evaluate and revaluate diagnose and review camera inspection. Get city sewer plans and review.
Call 811 before digging into the ground. Calling 811 will allow utility companies to come out and mark their utility areas so the contractor does not hit gas line or electric line or any other lines that maybe there.
Get city building permit and begin repairs to sewer system. If you need help, request the inspector to come out and show you how to handle excavation or anything.
The patching will depend on a few factors. The city inspector and the contractor will determine the back fill. Most of the time, it will be concrete that will be back filled into open holes.