First things first would be to determine how tech savvy this gentlemen is.
You have his facebook and email. now you can use a second account to befriend him find his interest and you can unlock his email using the secret question technic.
If he has taken guard on the flanks of possible social attempt he will most proably be alert for rats. But there are methods of getting passwords with little difficulty but that involves money which if you have may be a better recourse.