Rake the lawn to remove rocks, twigs and other debris.
Mow the lawn 1/2 inch high. This allows more light to reach the grass seed.
Scratch or scrape the soil in the bare spots to loosen it.
Add a starter fertilizer, at the rate listed on the fertilizer package, to the bare spot and scratch it into the top 1 inch of soil.
Sprinkle the grass seed onto the bare spots at the rate listed on the seed package.
Cover the grass seeds with a 1/4-inch layer of mulch, sand or grass clippings.
Water the lawn three to four times a day for two weeks. Do not mow the lawn until the new grass grows to 3 inches in height.