Pepakura Designer, computer software for PC, can be found here and the free version should sufficient. However, if you don't have that specific set of skills or know where to even start, you can download Pepakura templates from the internet. As you size them to your body, you'll generally be capable of creating the patterns that you'll need. Grab reference images of the armor from the game through any number of means (Google Image search, etc.) and then use large rolls of paper to draw them out.
Of course, if you have the drawing skills or are just looking for the challenge, you can free hand the patterns.
When trying to assemble patterns, it can be difficult to know where to start.
