NOT AN HP - Quanta NL5A (aka Proteus V) laptop - keyboard swap?

In case this is confusing the laptop is a rebadged Quanta NL5A laptop sold by CyberPower UK 6 years ago and also known as the Proteus V by another supplier. There is no option to specify anything other than the main brands so I opted for HP.

I've owned this laptop for around 6 years now and it's served me well. Unfortunately, the keyboard is not doing well. I have two key caps missing and a few other keys that don't respond at all. I managed to obtain a replacement and I confirmed it works by connecting the ribbon cable before trying to disassemble it. I thought it would be a case of removing screws until I had none left. It wasn't.

I've searched online using a lot of different terms and as far as I can tell there is no guide or helpful information on replacing it. I've taken it as far as I'm comfortable which was down to removing the motherboard but at that point I have a large metal plate separated from the motherboard by a transparent screen. The only remaining visible screws are holding the hinges down. I don't know if I'm missing something, if it's glued or what. I'm not comfortable prodding and prying without knowing what I might be doing since I can just use an external keyboard and it works fine. However, I want to replace the broken with the new one.

If anyone can help or point me in the right direction I would greatly appreciate it.