It is pretty easy when it comes to gaining root password to any Linux System as long as you have physical access.
This is how to change Fedora’s ROOT Password.
When your box starts up, You will see the GRUB screen…
What you need to do is, press the a Key instead of Enter
You will see something like the following…
kernel /vmlinuz-2.6.9-1.667 ro root=LABEL=/ acpi=on rhgb quiet
Add 1 at the end of that… So it looks like the following…
kernel /vmlinuz-2.6.9-1.667 ro root=LABEL=/ acpi=on rhgb quiet 1
This will make the box boot into Runlevel 1
You simply type passwd
Enter the new ROOT password and reboot the machine.
Same thing goes for Any Linux System as welll… All you got to do is, add the following kernel argument…
init=/bin/bash
And then just change the password…