as /u/stealthcoyote said, they go on with double sided tape. The thing is, proper prep is essential in order for them to stick over the long term. The louvers come with a small tube of 3M Adhesion Primer. But I found that single little tube was not enough for proper prep. So I bought two 3-packs on amazon So I had 7 tubes total, and ended up using 6 of them.
So if you do decide to buy those louvers, do yourself a favor and buy extra adhesion primer ahead of time. I was already into my install when I realized that there wasn't enough in that tube for a proper prep. And had to put everything away, and wait for the Amazon delivery.
You can still do it. Couple things I would recommend though, is maybe use a bit of 3M primer 94: https://www.amazon.com/gp/product/B0088P06AS on the back before applying vinyl. Then, you'd want to get an exacto knife and painstakingly cut around the grill. Easier job to do if you take the PSU apart, but I do not recommend you do this.
For the strips I just wire-tied them so you don't have to worry about adhesive ever coming undone in the summer etc. As for the bass control are you sure you actually need this? I've had a handful of systems and if it's been properly tuned with your system at the amplifier (especially for the types of music you listen to), you shouldn't be changing the amount of bass enough to justify needing a quick access dial. With that being said, if you really need this dial I would get some 3M Primer Pens which will prepare the little area that you are trying to stick the bass control to be bondable.
Regarding the "complicated spots" in pict #6... It looks like the vinyl In the corner area is not sticking well. These spots can be difficult. Try this stuff next time. It will keep the vinyl that is stretched into the low areas from wanting to pop back up. http://www.amazon.com/3M-Primer-94-Wrapping-Application/dp/B0088P06AS
OK, what you'll want to do, is place some primer: https://www.amazon.com/gp/product/B0088P06AS around the edge of where the vinyl will go, give it about 5 minutes to dry, then apply the vinyl. smooth it out with a squeegee: https://www.amazon.com/gp/product/B07F46PC19 and trim about an 8th of an inch over the project boundries. Then apply some edge sealer: https://www.amazon.com/gp/product/B005LDH83S so that the ends don't curl up. Sorry if that is a quick rundown, there is actually more to it then that, like using a hair dryer and such, it was a long night and I'm tired as hell. But like I said, currently working on another build for my YouTube channel where I show how it's done. Will probably be another week (probably this weekend) till I can get it done and uploaded. That probably isn't in your time frame, but there should be tons of videos out there showing how it's done on a car. The process for a PC isn't much different and actually quite fun.