I was writing this to someone in a PM, but then decided to just post it - in case someone might be able to use these instructions. Sorry - I was not planning to write up a DIY, so no pics, except the final product, but its pretty straightforward, so I doubt anyone would have any issues.

I'm not a professional installer. I'm simply sharing my experience, so use at your own risk. Always use common sense when working on anything and if some of my instructions do not make sense to you, consult a professional.

Tools and supplies:

-pre-cut vinyl tints
-bottle of soap water. I used a smaller bottle, but expect to use at least a liter, so just get an old soda bottle, clean it THOROUGHLY to make sure that there is no residue of ANY kind left inside the bottle and fill it to about 75% with water, add about a teaspoon to a tablespoon-worth of dish soap. Shake really well to make sure that the soap is stirred finely into the water. (the more concentrated the soap - the less you need, mine was really concentrated, hence my proportions)
-I used two, but one will do NEW (NEVER USED) microfiber towel(s).
-hairdrier/blowdrier or a heat gun. I used a good quality hairdrier and alternated from hot to cooler air settings as I worked through the film. Heat gun might be a bit of an overkill
-REALLY FINE needle - AS SHARP and as thin as you can possibly get. I'd actually recommend going to stores and finding the finest point needle you can have, bc this will make a HUGE difference on the finish.
-razor blade
-various cleaning and detailing tools and materials to clean off the surface before the install.

I strongly recommend you ask someone to help, because certain parts of the install you will be short-handed with only two hands.

Installation:

CARDINAL RULE: YOU ARE ALWAYS WORKING YOUR WAY FROM INSIDE OUT. GO FROM THE CENTER OF THE OVERLAY AND WORK YOUR WAY OUT TO THE EDGES.

1. Clean the headlights (taillights - whatever it is you're doing) thoroughly with regular car soap and/or dish soap. Wipe them down with 50/50 alcohol/water solution. Wipe them dry. It is crucial that you clean the surface very thoroughly and make it spotless. If you have any tar or any other road residue on the surface, use special cleaners to make sure you clear everything off. The better you clean the surface - the better your final product will look. Make sure that there is absolutely no fatty stains on the surface. I also bought and used a special spray that is used to clean the glass during tint applications, but that's not necessary - and it wasn't any more effective than soap water.

2. Wet the surface liberally with the soap water. You'll need your "helper" here: Ask your helper to pour soap water ahead of your application of film, then you take the film and start applying it by "unrolling" it onto the surface from one end to the other. This will ensure that there is moisture under the film, so that you can move it around.

3. Once the entire overlay is on the surface, move it around and position it as you want it. If the film starts to dry, pour more soap water. Its even ok to peel off a little bit, but very carefull, so that you touch as little of the adhering surface as possible - try to catch it by the very edge in a place which will be likely trimmed off later anyway. As long as you keep the surface well wetted with soap water, you can take as much as an hour repositioning the film, so don't hurry - just make sure your helper pours when you tell him/her to and that you have enough soap water. Keep in mind, that in most cases with curved surfaces you will not be able to make the film fit completely until you've heated it up, so your goal when positioning the piece is to make sure that there are no folds, no big bubbles and as few bubbles as possible altogether. Obviously, you wanna position the overlay so that it is ready to be dried.

4. Once you've positioned the overlay, take the microfiber towel and start working the moisture out from under the film. This is something you'll kinda learn in the process, but your goal here is to keep the overlay steady and at the same time work out the bubbles and dry the whole thing. Don't get too carried away doing this - just do the best you can and move on to the next step.

5. This is the most crucial step - have the helper hold the blowdrier and start doing step 4 in conjunction with your helper drying and heating up the surface that are immediately working on by blowing on it. Depending on the type of blowdrier/heat gun you're using, you might have to hold it closer/further away from the surface, but make sure that you're only drying the immediate area that you're working on at the moment. Remember: once you start heating up the overlay it will start sticking, so if you see that you're messing up, IMMEDIATELY turn away the blowdrier and pour soap water on the spot and start over. If a couple of bubbles are left after the blowdrying, its ok - that's what the needle is for. This is a sort of a tedious process too, bc you'll have to control the entire overlay while shaping it and working out the bubbles at the same time. But it cannot be that complicated, as I actually learned it as I went, so I don't think you'll have any problems either.

6. Once the surface dries, grab your needle and the MF towel and go to work on the bubbles. Try to move the bubbles as close to the edges as possible before popping, so that they are as invisible as possible. Also, try to pop them at a 90 degree angle, bc popping them at any other angles tends to leave a bigger "scar".

7. Take your razor blade and very carefully trim any excess pieces of film.

8. Pop a brewsky and celebrate