Dish Soap

• Cover the oil spot with grease-cutting dish soap. Use a stiff scrub brush to vigorously scrub the spot. Pour hot water over the spot and continue scrubbing until the oil spot is gone. Rinse the spot with more hot water until there are no traces of soap.
  
  

Trisodium Phosphate

• Fill a bucket with 1 gallon of hot water. Add 1 cup of trisodium phosphate. Stir up the mixture until the trisodium phosphate has completely dissolved. Pour the trisodium phosphate and water mixture onto the oil spot. Let it sit for 20 minutes. Scrub the spot vigorously with a stiff scrub brush until the oil is gone. Rinse the spot well with water from the garden hose.
  
  

Powdered Laundry Detergent

• Sprinkle powdered laundry detergent onto the oil stain so it's completely covered. Slowly add water while scrubbing the spot until a thick paste forms. Scrub the spot vigorously with a stiff scrub brush and the paste. Let the paste sit on the spot overnight. Add more water to the spot the next day and scrub it again. Rinse the floor with water from the garden hose.
  
  

Commercial Grease Remover

• Commercial grease removal products can be found at most home improvement stores. They are specifically designed to remove oil stains from concrete surfaces. Follow the instructions on the bottle for specific usage directions, since this will vary among products. In general, you will likely need to absorb as much of the oil as possible before cleaning the garage floor with the product.