Obtaining a Root Shell on Linux (Ubuntu/Kali Only)

How to get a root shell without any issues (Note: This method works only on Linux OS like Ubuntu and Kali).

start the machine and after see the grub loader:

press E Button

and see this line:

ro quiet  -----> and you need to replace with this
rw quiet init=/bin/bash

Finally:

press ctrl+x and you get the root shell. ;)