It should be very simple. In a perfect world, all you'd need to do is add the following to your pop-up's template, and the "Login With Facebook" button will appear.. and work:
{ JFBCLogin} (without any spaces)
In the real world, we've seen some issues some very Javascripty pop-ups that can cause conflicts. I don't know QLogin, so I can't say whether it would be a problem. We are working on an updated solution that should work around most of these issues, so we should be able to help you pretty quickly if you do have issues. If we can't help, we have a 30-day money back guarantee which will hopefully satisfy you as well
Good luck, and thanks for your interest!