Best way to gain access on RHEL server without root password is booting it in single user mode. This is only possible if you have access to the physical console.
How to recover sdelements password
Restart the system and at the beginning of the boot process. It should be counting down at this point and says: "Press any key to enter the menu". In this case you would hit any key.
Now you would see the grub menu showing current linux version. Press e for edit
on next grub menu you would get three options. Select second kernel option and Hit e to edit the boot kernel options.
You would now edit the main kernel options, adding either single or even just 1 at the end. and press enter
Once you have completed that hit enter, the b for boot.
You are now in single user mode, and be auto logged in as root.
Now you should be allowed to change your sdelements password. change the sdelements password and reboot system
now you could login with new password.