Should be pretty simple using parts already designed on thingiverse. That said, you would lose quite a bit of X going dual side-by-side. I would not recommend it. I have dual on my Cloner and let me tell you, it's a pain for as little as I use the second one. It seemed like a great idea, but it has a tendency to get in the way. At least in my experience. I have pulled the second nozzle while not using it.