3 Ways to Remove a Sticker from Plastic - wikiHow Soak the label in cooking oil. Submerge the plastic in a container of cooking oil for 12 to 24 hours. Canola, vegetable, and other oils will soak into the sticker and loosen the adhesive. This will make it easier to remove later. You can try the method again if it doesn't work the first time and then gently peel the sticker off with a razor blade.