Incredibly difficult. There are no step-by-step instructions. You must figure out the folding sequence yourself by pre-creasing the entire sheet and "collapsing" it simultaneously. 4. How to Read Advanced Origami Diagrams
Many regional origami societies publish annual convention books packed with complex PDF diagrams. Notable organizations include: complex origami pdf
You will need sheets measuring at least 14x14 inches (35x35cm) to 27x27 inches (70x70cm). Incredibly difficult
If you are looking for free, legal PDFs, your best bet is the "Convention Books" published by origami associations. These books often contain diagrams from the world's top folders. complex origami pdf