I unfolded the helmet in two pieces, partially because I'm horrible at 3d modelling and didn't want to join them and partially because I thought that if I were building this helmet I'd want it to be in two pieces so I could actually take the front part off/slide it up. I don't know.
Here's another file that Brandon originally unfolded that I've been getting a lot of requests for. I never saw his original, but it's probably simpler than this one. This looks like it would be a pretty difficult build, especially around the "mouth" area.