Just a word of advice; never download anything that is called a "facebook cracker" from google or youtube, as these are all RATs.
As far as your problem goes, I would just use a little social engineering to gain this accounts password.
To do this you can send your victim a fake email impersonating Facebook security. Say something about how they've logged on from a different location, and their account could be compromised. Ask them a whole bunch of non-sense questions to make the email seem more authentic. After that ask the question "What was your last known password?" If the victim is dumb enough, they will reply with their password.
For the fake mailer, Click Me!