First of all, I want to thank you for this guide, literally saved my day last week and has been user-friendly enough even for a 15 years away from Linux user to understand.
I only upgraded the kernel to 5.7.11 (as of July 29th) which also fixes nVidia Graphics, so if someone is struggling about it with 5.6 or with the patching of 5.4 (I got a lot of errors on the diff command so I went on to the latest stable kernel), this is a good option.
And if you want to update the tutorial, the 5.4 kernel patch is not working anymore (at least, it didn't for me).
Code:
mkdir kernel5.7.11 && cd kernel5.7.11
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.7.11/amd64/linux-headers-5.7.11-050711-generic_5.7.11-050711.202007290540_amd64.deb
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.7.11/amd64/linux-headers-5.7.11-050711_5.7.11-050711.202007290540_all.deb
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.7.11/amd64/linux-image-unsigned-5.7.11-050711-generic_5.7.11-050711.202007290540_amd64.deb
wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.7.11/amd64/linux-modules-5.7.11-050711-generic_5.7.11-050711.202007290540_amd64.deb
sudo dpkg -i *.deb