Janyse

I have several potted banana trees in my backyard. I want to know if anyone can tell me how to prepare them for winter. I live in Oklahoma City. We had temperatures that reached freezing last night and my poor banana trees look awful. Is it to late to save them. I have read that I need to cut back the leaves and remove the soil from the roots. I just don't know what to do next. I have a garage or an attic that I can place them in. I just want to know if I need to put them in a container or wrap them in plastic. Also, do they need sunlight or water while they are dormant?

Thank You!