Place both the ice cream and the root beer into a blender, and mix for about 30 seconds on puree.
It's important to start slow with your blender to avoid marking your freeze too slushy.
You don't have to stop at just root beer. You can make this with Coca Cola, Dr. Pepper, or any other soda you may like. You can also add flavorings if you desire. A Cherry Dr. Pepper Freeze has always had a special place in my heart.