Renovation is the process to use when your lawn, for whatever reason, needs to be totally replaced with a new lawn. The process usually calls for re-seeding, especially for cool-season grasses, or plant plugs, sprigs or stolons for the warm season lawns. Sod is not usually considered a renovation process. Timing for this project is important and depending on your geographic location. For seeding, the process is usually started in late summer so that the lawn is established before the first heavy frosts start settling in. Warm season grasses are usually done as soon as the soil warms up enough for seeds to germinate (typically, late spring).
Step One: Apply a non-selective herbicide such as Glyphosate (Roundup-use the higher strength version). A glyphosate herbicide kills what's on top of the soil as well as what's below the surface, yet doesn't remain active in the soil, so it's safe to plant again. Give the glyphosate time work. Let the lawn turn completely brown and then give it another week before continuing. At the end of that additional week, take a close look at the lawn to see if there's any sign of new growth. If so, spot treat again. Wait another week, and if necessary, spot treat once more. These are important precautions that will pay off in the future.
Step Two: After you are completely sure that everything is dead, mow the dead lawn. It'll probably raise a few eyebrows from nosey neighbors, but what do they know? Mow as close as possible and bag/rake the clippings. The remaining dead plants will provide natural mulch for the new seedlings. Too much dead plants and the new seed will have problems germinating.
Step Three: So far, everything's been fairly easy, now we're getting into the good stuff. Cultivate the soil. This calls for some power equipment you probably don't own. What you'll need is a dethatcher or power rake. A tool rental should have one. Go over the lawn first in one direction and then in another direction.
Optional: If your soil is heavily compacted, aerate it now.
Also, you can combine the cultivation and seeding process by using a slit-seeder. This actually cuts through the dead turf and plants a seed at the same time. Do the same routine of going one direction, and then in another direction. Slit-seeding is only recommended for non-compacted soils.
Step Four: Apply the seed, plant plugs, sprigs, or stolons. For seeding, use a quality seed of a grass type suitable for your climate. Use the rate on the label for establishing a new lawn. If using a slit-seeder, set the rate slightly above ½ the rate and do it in two directions as described above.
Step Five: Put down a starter fertilizer over the entire lawn according to label directions.
Step Six: Keep the seeds evenly moist until it germinates. The taller the seedlings get, cut back on the number of waterings and increase the amount of water. Cut the lawn when it reaches 2" — 3". Don't apply any weed controls, even if some pop up. Wait till next spring for cool season lawns or the fall for warm season.