Freeze the gum: place an ice cube directly on top of the gum, or place larger items in a resealable bag in the freezer.
Once the gum has cooled, you can try gently lifting it off with a blunt object such as a spoon.
For any left over chewing gum stains, apply a liquid laundry detergent, like Surf excel Liquid Detergent, directly to the stain as a pre-treatment. Be sure to read the product’s instructions and to test on a small, unnoticeable area first.