Reset Root Password

1. enter GRUB2 edit mode

2. modify linux-kernel string by adding rd.break at the end

3. press CTRL+x to boot with entered options

4. use chroot to mount /sysroot to / chroot /sysroot, pwd should read /

5. remount the root file system in read/write mode mount -o remount,rw /

6. run passwd to set new password passwd

7. create hidden file .autorelabel to run SELinux relabeling on all files touch .autorelabel

8. exit the chroot shell and reboot

GRUB2