Apply a concrete degreaser onto the concrete surface. Allow the degreaser to soak into the surface until all stains and/or spills are softened. Follow directions on product, as amounts and soaking times vary depending upon the severity of staining.
Scrub the degreaser into the concrete further with a stiff-bristled brush. Use a pressure washer filled with clean water to remove any concrete degreaser residue.
Mix 7 parts concrete resurfacer mix from one of the 40-lb. bags with 1 part water in a 5-gallon bucket; the total amount varies depending on the severity of the cracks. Use a pointed trowel to scoop a small amount of concrete resurfacer onto the cracks. Force the resurfacer into the cracks as much as possible with the pointed trowel.
Smooth the surface of the crack even with the surrounding concrete using the flat side of the pointed trowel. Allow the repaired areas to dry completely overnight.
Wet the concrete surface with water using the pressure washer. Remove all standing water with a long-handled squeegee.
Place 2.9 quarts water into a 5-gallon bucket. Pour 20 lbs. concrete resurfacer into the bucket, and stir the mixture with the mixing paddle attached to the power drill. Mix the bucket contents until the mixture is free of lumps and has a pourable consistency, adding more water if needed.
Pour the concrete resurfacer onto the concrete. Spread it with the long-handled squeegee. Concrete resurfacer has a 20-minute working time, so do a few small sections at a time until the entire surface is covered. Allow the mixture to set for five minutes.
Sweep a stiff-bristled broom over the concrete surface to create a non-slip surface. Allow the surface to dry for 24 hours.