Spray your lawn with a broad-spectrum herbicide that contains glyphosate to remove existing grass. Glyphosate kills existing turf by inhibiting its ability to produce proteins. Wait at least two weeks before sowing grass seeds.
Push a power dethatcher across the lawn to remove dead grass and thick thatch. A thick-thatch layer of over 1/2 inch contributes to poor grass root establishment and prevents grass seeds, which must have adequate soil contact, from germinating. Rake up the dead lawn debris.
Push a core aerator over the lawn. Core aerators remove plugs of soil to increase airflow and soil drainage.
Pour starter fertilizer into a rotary spreader and distribute over the yard. Starter fertilizer is high in phosphorous, which encourages strong grass seedling development. Distribute a starter fertilizer with a NPK amount of 5-10-5 at a rate of 20 lbs. per 1,000 square feet. Work the starter fertilizer into the first 2 to 4 inches of soil.
Broadcast grass seed over the soil. The amount that you distribute depends on the type of grass you are growing. For instance, Kentucky bluegrass is distributed at a rate of 2 to 3 lbs. per 1,000 square feet. Cover the grass seed with 1/8 inch compost. Water the lawn.