The quickest way is to cut out the sticker and apply directly to the hull. One problem though, if its not lined up correctly you will have trouble taking if off and reapplying. To help with this use the wet method. Take a bowl of water and mix with some dish washer detergent. Use about a table spoon full to 3 cups of water. Next apply some of the soapy water to the area where the sticker will go. Then take off the sticker backing and dip the whole sticker in the soapy water. Now when you apply the sticker you will be able to slide it around until its lined up perfect. After applying the sticker, you can use a wet cloth to squeegee out excess water from behind the sticker. Slowly taking your time to remove most of the bubbles. Any left over bubbles after the sticker has fully dried can be flattened using a new, very sharp exacto knife. Poke a tiny hole into the center of the bubble then flatten it out. Once you are done applying the stickers, they can be spray painted with clear spray paint to help stop the edges from curing up. Please read some of the other articles on spray painting in the "Tips and Info" section for more details.
Below is a video by Traxxas, They talk about the water and soap method at the 2 minute mark.