I looked at Pepakura briefly when I made my Gears costume. That's the software that takes the 3D wireframe and flattens it out into printable sheets. It also marks up the pages so you know where you have to cut, where you fold out, and where you fold in.
It's shit like this that makes me wish I'd have paid more attention to math in school. It all comes down to math.
You can find all sorts of files out there for it. Lots of Master Chief costumes, etc. Be ready with some extra paper though. To give you an idea of scope, the Chief's helmet alone was something like 90 printed pages. The chestplate armor was in two pieces, at around 170 pages each.