https://www.youtube.com/watch?v=aHdh9AIT... This is from a Spanish youtuber, but the video has no narration. It's not really needed. It's an INCREDIBLY easy repair compared to a lot of tablets. If you're not experienced at removing glass or repairs in general, you might want to consider NOT using a metal tool to remove the glass, but something like a plastic pry tool, a thin plastic spudger, or an old credit card actually works VERY WELL for this purpose. A plastic butterknife is also a great option for removing the rear casing clips. Metal tools pose a significant risk of scratching or damaging the LCD underneath, but metal carving tools like the one in the video can make the process WAY faster if you're experienced. Also, if you do not have a Heat Gun like in the video, make sure you use a hair dryer on a high setting, and focus on the area of the glass you're planning to separate for a good 60 seconds or so before trying to work a tool in. Take your time and this is a very simple repair.
I have this same issue, but ive thoroughly inspected that flex cable, and it's not damaged at all. Ive even unwound it down to where it connects at the end of the day, and it's fine. The vol down rocker works, but not the up, and the power button doesn't work.