› how-to-remove-a-sticker7 Clever Ways to Remove a Sticker from Plastic Spray the cleaner over the sticker to saturate it and let it sit for a couple of minutes. Press the flat edge of a putty knife on the plastic and push it gently beneath the sticker. Use some force while you slide the adhesive away from the surface. After you remove the sticker, inspect the area for sticky residue.