En passant? If that is an option, I'd do it in front of the queen-rook combo on the e-file. Otherwise I'd probably have to sacrifice the bishop to get through the pawn chainmail. Doing it on the far right is a bad idea because that allows my opponent's strong pieces to get me, so I'd move the queen and do it on the right.
I would also move the other rook in to the b-file before doing it to allow the pawn to attack the bishop. White has a material advantage in this position with the extra rook, so the loss of the bishop should not negatively impact White's winning chances.
If I were black, I would wait for White to make the sacrifice, since I retain more of an advantage by doing so.