Step 1: Research
You can find them all over Google or my personal favorite was the 405th.com they have pix of just about every conceivable angle.
Step 2: Skeleton
Download the Pep files for the model of chief you want (available on 405th). Once you have them all set up and ready to print make sure sure you print on a good weight card stock. Personally I feel the heavier the better but if you have small hands and low grip strength just make sure it is thicker then pain paper.
Dear lord there are a a lot of shapes to cut out! I recommend doing one limb at a time so you don't get your parts mixed up.