Hmmm I think the diagrams just look confusing... basically what you're doing is you're taking those pleated layers, unfolding it, and using precreases to make them into a longer flap. Step 36 shows how to fold the layers back down, and 37 assists with with that.
I'd fold it and take some pics right now but it's almost 1:30 at night so I'll check back later,

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