Question. Possible ba na i-convert ung server into virtual machine / vm. Para kahit VM lang eh ma-access namin ung system and reset ung admin password kung puwede.
There's a way to change the root password in Linux via booting from the GRUB menu.
During normal start up, kung may option ka to select what OS to load, select the default "linux xxx" and hit "e" to enable editing the boot loader argument.
Then look for the line that starts with the word "linux" or "kernel"
replace the "ro" with "rw init=/bin/bash"
Hit F10 or whatever the instruction is to boot the operating system
You should end up with the root command line. Type in "passwd" to change your root password
Just tested this with Ubuntu and CentOS. Your mileage may vary