Carnitas: Combine oregano, cumin, chile powder, and salt into a small bowl. Rub spice mixture over pork and place into a slow cooker (fat cap side up).
Squeeze orange juice over pork and add orange quarters, onion and cinnamon sticks to slow cooker.
Close lid and cook over low heat for 9 hours or high heat for 6 1/2 hours. (internal temperature should read ~190F˚)
Once pork is fork tender and falling apart remove most of remaining fat cap and discard.
Discard orange, onion and cinnamon sticks.
Transfer pork to a rimmed baking sheet and shred using two forks.
Spoon a few tablespoons of braising liquid from slow cooker over shredded pork.
Place baking sheet under broiler and broil for 2 to 4 minutes or until some edges become crispy.
Remove from broiler.
Assembly: Lay tortilla onto a clean surface and spread about 1/2 cup guacamole over the tortilla in a shape of a brick. Top with about 3/4 cup carnitas, ½ cup cilantro rice, pico de gallo, cheese, guacamole, and beans.
Carefully fold sides of the tortilla inwards, to the center of the burrito, then starting from the end closest to you roll until the burrito is fully wrapped and place onto a cutting board seam side down.
Repeat with remaining ingredients and serve.