Find a nice big bowl that holds all your bananas, then put them in it. Try to spread the bananas out as best you can so they aren't bunched up together.  As the bananas begin to thaw, they will inevitably leak some liquid, which is why putting them in the bowl is really useful. If you don't have a bowl around, feel free to put the bananas inside a plastic bag. If you froze the bananas in a bag in the first place, you can just use this bag. If you're concerned about flies or other bugs, cover the bowl with foil or plastic wrap. Try to time it so that you are ready to use them right as they become fully thawed out. Put the bowl somewhere where it receives a lot of light if you want to make it go a little faster. Letting the bananas sit for 2 hours is just a rough estimate, this may take more time or less time depending on the climate you are in.

Summary:
Put the bananas in a bowl to catch the leaking liquid. Leave the bananas to sit for 2 hours.