No problem. Here's what you'll need to make 6.5 gallons:

10 Lbs of Bananas (overriped is preferred)
15 Lbs of white table sugar
1 table spoon of baker's yeast (or 1 pack of turbo yeast)
1 tea spoon of pectin (this is needed to break down the fruit)
1 cup of mashed rasins (not required if using turbo yeast)
5 gallons of water

First peel and slice all of the bananas and add them to your fermentor. This will be easy if you use overriped bananas (they're solid black at that point). Next take out your frustration and smash the sliced bananas into an oatmeal type of consistentcy. Now in a large stock pot, bring half of your water (2.5 gallons) to a low boil and add the pectin to your banana mash and stir for 1 minute. Next dissolve 13 pounds of your sugar and save the rest for your finished product. Now add this mixture to your banana mash and stir for approximately 2 to 3 minutes. This will make sure that everything is well mixed together and will help the pectin break down the fruit into fermentable sugars. Next add the remaining water to cool it down to between 75 and 90 degrees F. Next add your yeast. If you're using turbo yeast please follow the directions on the package. If you're using baker's yeast take 1 cup of rasins and boil them in some water and then add them to your sugar and water mixture before you cool it down to the yeast's pitching temperatures.

^ I've made this 4 times and it's a popular recipie. I do get some requests for it on occasion, but everyone seems to want my peach brandy instead.