1. In the boot grub menu select option to edit.
2. Select Option to edit (e).
3. Go to the line of Linux 16 and change ro with rw init=/sysroot/bin/sh.
4. Now press Control+x to start on single user mode.
5. Now access the system with this command.
chroot /sysroot
6. Reset the password.
passwd root
7. Update selinux information
touch /.autorelabel
8. Exit chroot
exit
9. Reboot your system
reboot
That’s it. Enjoy.