Need help upgrading to Catalina.

So I was updating to Catalina from Mojave and everything was going so well until I realised I forgot to update some kexts... What an idiot! So now when I boot into Mac OS, it results in a black screen. I've tried running in verbose mode and nothing comes up—literally just a black screen.

I think it might be something to do with my graphics card / whatevergreen.kext, so I've tried blocking that kext and I've also tried bypassing my graphics card and just using integrated graphics, but I can't boot up that way either. When I boot up with IGPU, verbose looks like [image].

verbose mode with IGPU

So I need to somehow update my kexts without being able to see anything on the screen. Does anyone know how to do this or if this is even possible? E.g, could I boot up into Windows and access the HDD that has Mac OS installed or something?

Motherboard: Gigabyte Z390 Gaming XCPU: i7-8700Graphics: RX 570