What is the best way to remove AIR-SHIELD LMP from concrete?

Paint stripper will work well. Colder temperatures will make it more difficult to remove. Mechanically remove as much as possible. The paint stripper will dissolve the remaining AIR-SHIELD LMP, causing it to wet-in to the concrete. The more that can be removed mechanically before attempting to remove with a stripper will help decrease any staining that may be permanent.