Sammy,

If the stalks of the bananas are firm, you are o.k. Don't do anything
until you are sure you won't have another freeze, then just cut off
the brown, and make sure the new growth can get out of the top. I
actually cut the tops of mine back about 6 inches once after a freeze,
and they came out fine. If they're mushy, cut them back to the ground
and let new shoots come back up from the roots. I chop up my dead
bananas and put them around the other plants, because they still have
a lot of potassium in them, and they love that.

Fertilize middle of next month with a high nitrogen fertilizer. I use
lawn fertilizer, but make sure it's not weed and feed. If there is no
new growth from the tops or the roots by May, take them out.