Break the root password:-

Interrupt while booting and press “e”

Move the cursor to the line start with linux16 and type rd.break next to LANG=en_US.UTF-8, then press ctrl-x to boot.

# mount –o remount,rw /sysroot/

# chroot /sysroot/

# passwd root

(Than enter the new password).

# touch /.autorelabel

# exit

# exit