Besides copying a file to / and execute, I think the steps 6 to 11 are unnecessary.
It looks for me the hole point is to change the grub kernel line to add “systemd.unit=multi-user.target”. But the standard target in systemd is “multi-user”. So start a Kernel without that option should not make a difference.
The other think is, you should never login in as root on a Login screen. Use as described by BS86, sudo, sudo su or su.