Sweep or rinse the area to remove loose dirt and debris
Wet the cement surface with clean water
Apply a rust remover made for concrete or a paste of lemon juice and baking soda
Let it sit for the recommended time or until the stain begins to lift
Scrub the stain with a stiff nylon brush
Rinse thoroughly with clean water
Repeat if needed for stubborn stains
Use a pressure washer if appropriate for the surface
For heavy stains, apply oxalic acid or a commercial concrete rust remover according to label directions
Neutralize and rinse the area well after using any acidic cleaner
Dry the surface and check for remaining discoloration
Seal the cement after cleaning to help prevent future staining