I'm a bit unclear as to what the big deal is here? I did my Tempest one and didn't have a clue at the time. I just carefully peeled it off, lined it up (from no particular end IIRC) and just smoothed it on, either with my hand or a cloth and certainly no soap or anything like that! Gently and easy does it, bit by bit basically.
Thinking about it, I did the StarGate too and that held a lot of potential for going south as it was high gloss but it again was fine. I think the trick it to be as light as you can without getting bubbles initially so that you can lift it off (carefully) if it's not perfectly lined up. Once you're lined up, go for it. Again, gently does it.
I did the artwork on the sides of my Initial D while the sides were still on the cab. And on my own. That was fun and games but came out perfect! If this stuff was difficult then I assure you I'd have screwed one up by now. I have about as much patience as the proverbial bull in a China shop!!!