It's just as hard and as easy as precisely placing a sticker. Well, maybe a bit trickier for the front part, because the large hole for the screen doesn't help keeping the skin in shape while handling it, but it's really no such a big deal. You can practice with a large sticker, where you cut a big hole, and try to place it in a paper sheet where you have drawn a Kindle
It also depends on how picky you are. I know of someone who bought a skin for a different model and placed it partially covering the screen... and he doesn't seem to care about it, while it would drive me mad