Set Default Kernel entry in GRUB2

Problem: After installing Wireguard in Ubuntu 18.04. the kernel vesrion 5.3.0.1026.13 (linux-image-gke-5.3) is automatically installed, as well. However on my system it broke several things like display-resolution and keyboard… So i’d like to reset the former kernel linux-image-generic 4.15.0.106.94 as the new default kernel in GRUB 2 again. Solution: 1) Backup grub config file: > sudo cp /etc/default/grub /etc/default/grub.bak 2)...