Thoroughly wet the surface to which the decal will be applied, with a solution of warm water to which has been added a couple of drops of liquid soap. The soapy solution will allow you to carefully move the decal to the final position. Remove all air bubbles from the decal (sponge or squeegy, and pin for the stubborn air bubbles); allow to dry. I've used this method for putting decals, numbers, and also decorative tape (pin-striping etc.) on model sailplanes (largest I have has wingspan of just under 10 feet).

- Wil