Reset Mac OS Admin Password

If you have lost the only admin password for your Mac OS you can try this:

This may not work if protection has been put in place.

On boot hold [Command-S] for single-user mode this will display a terminal prompt as root.

At the terminal type:

mount -uw / 
rm /var/db/.AppleSetupDone 
shutdown -h now 

Now reboot

Tested on MacOS 10