Trim unwanted fat from the pork and discard.
In a slow cooker, add pork, salt, cumin, black pepper, oregano, cinnamon, bay leaves, cayenne pepper, garlic, chipotle peppers, tomatoes, and orange juice. Cook on low for 8-10 hours.
Meat is done when it pulls and flakes apart with a fork. When it is cool enough to handle, lift the meat from the juices and place on a large platter or cutting board. Shred the meat to bite-size pieces.
Skim the fat from the juices and keep as a medium for re-heating the meat. To reheat, place carnitas in a baking dish and pour juices over top. Cover with foil and re-heat in oven. The juices are also really delicious as a sauce over the carnitas. It will be spicier than the meat itself, so be careful to taste-test.
Place carnitas evenly into tortillas. Top with avocado, goat cheese, salsa, and sour cream. Drizzle with lime juice and serve.