Place the pork in a large dutch oven with the orange juice, lime juice, garlic, cumin and salt. Add enough water to barely cover the meat. Bring the pot to a boil and then turn down to a simmer and let cook for 2 hours.
After 2 hours, (and by this point your house will smell awesome) turn the heat up to medium high, and continue to cook the pork for 45 minutes, stirring every once in a while, until all the liquid has evaporated and the pork fat as been rendered.
Once the pork is browned on both sides, it's ready to eat. Taste and season with a little extra salt if needed.