Booting GRUB Stage
STEP 2. Type ‘a‘ to modify kernel argument. Anytime you can cancel typing ‘ESC‘ key.
Modify Kernel Argument
STEP 3. Append 1 at the end of “rhgb quiet” and press “Enter” key to boot into single user mode.
Append 1 at the Screen
STEP 4. Type command “runlevel” to know the the runlevel where you are standing. Here “1 S” state that your are in a single user mode.
Type runlevel Command
STEP 5. Type ‘passwd‘ command without username and press ‘Enter‘ key in command prompt. It’ll ask to supply new root password and re-type the same password for confirmation. “Your are Done” Congratulation!!!
Type passwd Command