You can't fix what has happened. You can be hasty and possibly screw-up a potentially salvagable situation. I would cut some bananas, or a whole hand (top one) and bring them indoors to ripen and see how they turn out. That will give you some idea what to expect. Otherwise, when they are stiff, black and dry, there isn't any hope left. You might be surprised how well this could still turn out if you are patient and hang in there.

I found your pic very interesting, as that's what my Ladyfinger bananas often look like anyway. (I don't cover the bunches and assume it's a combination of lack of water--we're in drought here--and too much sun in summer/light frost in winter.) I just cut the entire stem down when some of the bananas start to go yellow (usually not even as yellow as those in your pic) and place them in the shed to ripen. They still taste good.

We're having very cold winter nights here now (it's fallen to zero degrees C over the past week) and I've noticed that of my three bananas growing in a row along the fence (Ladyfinger, Goldfinger, Blue Java), it's the Goldfinger that's suffering the most. Its leaves started to yellow as soon as the nights *began* to get cold, say about 10 degrees C. I don't know how this will affect the fruit as this is only its second winter and it flowered for the first time a couple of months ago, so the fruit is still small and green. But, as I said, it's the one that seems least cold hardy.