Immediately: Check the fibre content of the fabric. If it is acetate or triacetate, Do not use nail polish remover. Have the garment professionally dry cleaned. Otherwise, place fabric face down on paper towels and apply nail polish remover to the back of the fabric. Replace paper towels with clean ones until the polish is gone.
Use Dynamo and the hottest water safe for the fabric, as care label recommends. If some colour remains, wash again and use Sard Wonder Stain Remover as per label instructions.