Out of my Depth

[darksage]

I have recently acquired a Mac book from my step daughter that seems to have had a Firmware password set. Clearly Apple doesn't care. I have Created a usb to try to remove the password but it doesn't work. S i am left with tring to figure out what the password is. I have tried John the ripper and I was very unsuccessful. I know how to Open programs in Cmd but I dont know how to give them commands or even how this works. The mac wont boot from cd or usb and the Hdd has been erased. Please Help