Wipe clean the surface you are applying the sticker/decal to with a mild cleaner. Allow to dry.
Carefully peel off the backing layer from the sticker/decal. Only the vinyl and the clear transfer layer should remain.
Place your decal on the surface. Use a credit card or a squeegee to rub and smooth the sticker/decal onto the surface.
Now remove the clear transfer layer by peeling it off starting from the corner.Only the vinyl sticker/decal should remain.