Sure, just log onto your BFP4F account and select buy more funds. After that you'll want to go down to the right hand corner of the screen where it will say something like "earn more funds", from that point simply fill out the offers given and wait for your reward! I suggest creating an alternate E-mail account because you will end up with a lot of spam mail. Next time use the forum search before posting, I've seen a couple of threads on this and someone even posted a video.(Also make sure to select the free offers)
One more important note! make sure to take Screenshots of EVERY completed offer! if you don't receive your funds after a couple of hours simply go to the support page. (which should be in the upper right hand corner of the Sponsor pay page) than simply upload your proof add your problem and send it to them!