It's not the easiest thing to do but if you're careful, it can be done. The larger the surface area you are covering, the harder it is to apply. I owned a sign shop for years and still do some lettering installation when the need arises. Vinyl lettering stretches and conforms to irregular shapes very easily.
Here's the process...
Tape the lettering in place with the backer paper still on. The lettering will come in a 3 layer sandwich with the lettering in the middle, backer paper (just like the backer paper on a bumper sticker) and a top layer of transfer tape. The transfer tape is what keeps all the lettering in place and properly spaced while you're applying.
Once you get the whole thing in place with tape, straight, centered, etc., create a hinge with masking tape along the entire length of the top edge. This way you can lift the lettering up from the bottom to remove the backer paper and keep the lettering where you want it. Then you need to hold the lettering out at maybe a 30 degree angle to the hull with one hand while you squeegee the lettering in place from the top down with a Bondo applicator or a designated vinyl squeegee from the sign shop you use. The trick is to only allow the lettering to come into contact with the hull when pressed into place with the squeegee. Do not pull the backer paper off and drop the lettering in place, then squeegee it down, you'll get all kinds of bubbles and wrinkles that way. By squeegeeing the lettering down while holding it away at an angle, you push all the air out from behind the vinyl.
There are lots of little tricks...if you get your lettering online and want someone to walk you through the process...send me a message and I'll help you out.