Challenge - Hacking/Breaking into a PA-500 to change the password

I was given a Palo Alto PA-500 to study on at work. Which is great :)

Only caviat - no one (and I mean no one) knows the password. Or anything about this particular one, really.

So the challenge giving to me is, without factory resetting the device, changing the password on the PA. Does anyone have any recommendations on how to accomplish this?