I remove the backing on the lighter color, and stretch it out on the glass holding in place at each end with tape. I then overlap about 1/4" with the darker color and also tape in place. Then using MonoKote Trim Solvent, I dampen a rag (do not make wet) fold the dark color back and apply to the light color you will hardly see any difference but when you place the darker color down it will set very permanent start in the middle and work both ways toward the ends. (I allow several hrs before removing). It will be like one piece with two colors.