Dampen clean cloths in acetone. Lay the cloths over the nail-polish stain. This will help prevent the stain from drying out before you can remove it.
Dampen another clean cloth with acetone. Lift up one of the previously laid down cloths and blot the stain’s edges with the cloth you just dampened. Use a new portion of the cloth once one area gets covered in nail polish. Work your way toward the center of the stain and only uncover areas when you are ready to clean them. Use as many clean cloths and as much acetone as needed to remove the stain.
Apply a carpet dry-cleaning solution to a clean cloth and blot the area to remove any remaining dye, working from the edges of the stain toward the center.
Mix 1 tablespoon ammonia with 1 cup lukewarm water in a bowl if the stain remains.
Apply the diluted ammonia to a clean cloth and blot the area until the stain is gone, working from the edges of the stain toward the center.
Mist the area with cold water to rinse away residue from the cleaning solutions. Press a cloth into the carpet to pull out the cold water. Repeat the process until all of the residue is gone and the carpet looks and feels clean.