Most car decals can be removed by gently scraping a putty knife or strong, plastic card under the decal until it comes off the surface. Any remaining residue can usually be removed by rubbing an adhesive-dissolving agent on the affected area with a clean cloth.
Most decal removal techniques depend on the type of adhesive used to affix the decal or sticker to the vehicle and whether the sticker is attached to a glass, plastic or painted surface. Cars.com recommends using the heat from a hair dryer to loosen the glue of a hard-to-remove decal before working the putty knife or card between the two surfaces. Razor blades can be used on stickers attached to glass surfaces but not on plastic or painted surfaces, as the sharp edge could damage the finish.
Hard plastic decals attached with foam adhesive should be removed by cutting through the adhesive with fishing line or dental floss, then applying a noncorrosive adhesive solvent to remove the remaining foam.
If the decal or sticker has been attached for a long period of time, there may be some difference in color on a plastic or painted surface, which might require polishing or sanding to restore a seamless finish to the vehicle.