We Recommend defoliating the areas intended for sod using weed killer. One treatment should completely kill your old lawn and weeds.
After treatment you should now wait 7 to 10 days before removing the lawn. This will ensure that the root system of all existing weeds has been eliminated and that the soil is no longer contains the treatment.
To remove you old lawn we recommend using a sod cutter. Sod cutters can be rented at your local equipment rental stores.