Devil's grass is otherwise known as Cynodon dactylon in scientific terms. It goes by many names, but the most common is Bermuda Grass. This plant is listed as a weed by the USDA and is considered a noxious weed in three states. It is a challenge to remove from your lawn, but with a little persistence, it can be accomplished.
Spray the devil's grass plant with a glyphosate herbicide, aiming directly at the plant with as little overspray as possible. Follow the manufacturer's label for dosage and application. Allow a few days for the herbicide to work.
Sprinkle grass seed onto the spots in the lawn where the grass has yellowed from the herbicide and dead devil's grass. Leave the old devil's grass in place to serve as a mulch for the new grass seedlings. The newly planted grass should fill in the areas within two to three weeks.
Check the lawn periodically to make sure that none of the devil's grass returns. Spray again if needed.