First of all cut the grass low, then remove the felt, using a special Aerator rake. With a rake clear the lawn from all the debris from mowing and aerating. At this point scatter all over the lawn the appropriate soil for sowing, composed of peat mixed with sand and organic fertilizer, to create a bed that will host the seeds.
Then sow by the broadcaster method, taking care to spread the seeds over the whole surface of the lawn. Then use a roller to pass around the lawn, to make sure that the seeds adhere well to the soil. At this point you should water the ground, moistening it thoroughly.