Reset Root Password from GRUB (Linux)

Follow the steps below to reset the root password using the GRUB bootloader:

1. Restart your machine.
2. At the GRUB boot menu, select your Linux kernel entry.
3. Press E to edit the boot options.
4. Navigate to the end of the line that starts with linux or linux16.
5. Add one of the following to the end of the line: 1 or S or single.
6. Press Ctrl + X or F10 to boot with the edited line.
7. You will now be dropped into a root shell.
8. Run the following command to reset the root password:

passwd

Enter your new password when prompted, then reboot the system.