It really is a PIA even if the video makes it look easy. It comes in 5 foot by 4 foot sheets and is tough to do like that - the difficult part is the contours and edges. No body shop will do it. A decal guy quoted $75 an hour - time and materials.
So what I did was cut it down and patch it in by smaller pieces. Probably took about 15 to 18 hours total.
It's really just a peel and stick.
Clean thoroughly and Prepsol the boat. Use a squeegie to eliminate the bubbles as you peel the back from behind downward. - overlap the edges by ~ 1/4 inch
Make sure there are no air bubbles otherwise it will eventaully crack and lift. Use a heat gun or a hair dryer on the edges.