It isn't easy - and I suspect there is a machine like a mechanical pea sheller that does it faster, but simmer the seeds in water for about 15 minutes, then squeeze from the rounded end and the seed shoots out of the husk. It's kinda like chestnuts, by the time you go to all the trouble, you are bound and determined to like them. OTOH, the simmering time can include all kinds of flavorings, which actually do get picked up through the hull and flavor the pepita.