Xbox 360 RROD. I had been contemplating sending the box in to MS to fix it for me, but I figured it would be cheaper and faster to do it myself. I would say my understanding of electronics is limited but competent. I know what a heat sink is, for example. I know the difference between a GPU and CPU, and I understand the way stuff works in a conceptual sense. I've never been a soldering master. In fact, I'm terrible at soldering. I'm glad this fix was essentially thermal paste, heat sinks, and screws.
Went pretty well. However, either iFixit sent me the wrong size Torx screwdriver or else the size of the Torx screws on the IR receiver were wrong -- I don't know. Luckily, I had a set of Torx screwdrivers already.
Getting the film off the thermal pads included in the kit was an obnoxious task. I had to filet the film off one side with a razor blade, taking off a small but noticeable amount of the pad in the process. I thought about just reusing the ones that were already there, but then I figured these new thermal pads included in the kit must be an upgrade (I know nothing about the quality of thermal pads, fwiw).
The biggest pain was getting the x-clamps off. At times I thought I would damage the motherboard because I was applying quite a bit of pressure prying the clamp off the stud.
The whole process took about 1-2 hours. I followed the guide on the website and also used the accompanying video.
I went out and bought a heat gun to do the "reflow method." I justified the purchase by telling myself that a heat gun would be useful for other tasks in the future. I found one at Lowe's that was around $25 -- the cheapest one that had adjustable heat.
I also went out and bought some Goof Off to help clean off the old thermal paste. This cost about $3. I don't know if it was entirely necessary, though. I did pretty well with a blunt-ish flathead screwdriver and an exacto knife. I went painfully slow.
Beware of the incidental cost of home repair. I spent about $30 extra, but you could spend more than that, especially if you run into the same problem with the wrong size Torx screwdriver. You could also spend far less depending on what you have at home, what you can borrow, and whether or not you're going to attempt the "reflow method."
Also, I've learned this over the years, but label and/or organize the screws you take out. Don't just put them in a pile.
Take the box apart slowly and patiently to prevent breaking the case. If you're a person who gets easily frustrated because somethings not coming apart as it should, don't force it and just walk away for a couple minutes. Come back and see if you forgot a screw or something. If you're sure there's no screw, apply firm but controlled pressure.
When you put the box back together, you might be so anxious about getting it working again. I would suggest you be just as patient and methodical as when you took it apart.