That sort of depends - it is fairly traditional to roast in-shell (which makes the shell more brittle) and use rocks/hammer/teeth. This guy has a de-sheller/cr

That sort of depends - it is fairly traditional to roast in-shell (which makes the shell more brittle) and use rocks/hammer/teeth. This guy has a de-sheller/crusher, if you want to see: https://www.youtube.com/watch?v=S_Si67R1BjY https://www.youtube.com/watch?v=S_Si67R1BjY I would probably try to sort/bin by size (shake through progressively larger holes/screens, might need to fabricate something), then run it through the crusher, then again screen To expand a bit more, probably dual steel plates with fixed spacers (based on bin size) in a hydraulic press would be best. Roasting/dehydrating/waiting makes the shells brittle and would make that process easier probably.