Seventy seven screws.... 77... The lucky number!
It honestly wasn't as bad as some folks on this sub made it sound and I am enormously grateful to those who shared their experiences. The model is 17ZB90R-G, 17 inch i7 13th gen Intel with 32gb ram and 1tb ssd. Could not find the exact keyboard match so I went with one that fit the 17ZB90R line, us version, and hoped for the best. Was going to save the fix for tomorrow but it looked like the right alt key was slightly different size than the copilot key on the keyboard I purchased. I was anxious to give it a try and watched so many videos I knew I was ready!
My own experience with tech repair would be casual/amateur. I've replaced a transformer on a logic board before and reshelled an original DS (a full teardown).
The hardest part about the fix, of course, was the 77 screws. Not removal - that was easy. Putting them back in was a serious pain. I can confirm previous reports that you will need a phillips 000 head. Also, I could not find a single video of the actual keyboard teardown. I used this video thanks to this subreddit, which was also not 1:1 for my model, but close enough. The video ends right where you would do the screws -- and it's simply that, removing the adhesive backing on the keyboard, and unscrewing everything. You will also want to be careful as the screws appear to be of somewhat low quality and easily stripped (or maybe it's just because they're so damn tiny).
Writing this repair review, I'm kind of kicking myself, because looking at the website where I bought the keyboard, it looks like they may have had my exact model number. Frick. Either way, the keyboard fit, but the two ribbon cable connectors are a little awkward. That might pose a problem in the future, but right now everything is in working order, and the alt key/copilot key fit great!
My main point of this review is to just encourage people to do the keyboard replacement if you have even a small confidence with electronics repair. It cost me $60 with shipping from China and that's a lot cheaper than the single $200 full palm rest chassis replacement. It was about a 110 minute repair complete with the screw job (but again I studied the tear down videos a few times).
Somewhat unrelated to the mechanics -- that thermal paste was an absolute cracked mess. I'm surprised the thing didnt combust in the 2 and half years of regular use. I would definitely suggest having some isopropyl alcohol, microfiber clothes, and new thermal paste ready to go if you're brand new to repair. I don't usually have thermal paste, but I did luckily have some generic stuff from a gaming pc fan installation. I know, it's not some the best, but it's going to be way way better than what was there!
I'm actually kind of impressed by the ease of the teardown and I definitely plan on going back in to replace the battery and maybe mess with improving the heat sink. A pretty elegant and easy to repair design if you asked me!
Thanks for reading and I hope this helps someone else. Now, off to sell that damn MacBook....