I don't think you could force a win with the Bishop and Knight. You probably couldn't force the other one either. The B+N would sac a piece to kill the Pawn (at worst) and then you have a Rook vs a minor piece, which I think is a draw.
If you wanted to try, you'd try to get the Pawn to Queen of course, and the other side would block it with one piece and try to get some kind of fork or skewer going...it would rely on someone making a blunder I think.