Wait until the temperature is between 50 and 80 degrees Fahrenheit. Sweep the concrete surface to remove any dirt or debris. Spray any plants growing nearby with water so the chemicals will run off them if they come into contact.
Put on acid-resistant gloves and goggles. Stir the concrete stripper with a paint stirrer and pour it into a paint tray.
Paint a thick, even layer of the stripper onto the concrete with a paintbrush. Overlap each stroke so there is no missed section.
Let the stripper sit for one to six hours, or however long the package directions recommend. The stain will visibly lift out of the concrete. If the stripper dries out during the lifting process, paint more onto the dry spot.
Use a pressure washer to remove the stripped stain and the stripper. Start at the top of the concrete surface and work down. Rinse the concrete two more times to ensure that all the stripper is gone.