You have a couple of options for making the pork:
Combine the chili powder, paprika, garlic powder, onion powder and cayenne pepper. Rub all over the pork and store in your refrigerator all night. Then pick your cooking method.
OR
Add all the ingredients to your Instant Pot and set it for "Pressure Cook" for 2 hours. To speed up the cooking, cut into 1 inch cubes and set your Instant Pot for 1 hour.
OR
Add all the ingredients to your Slow Cooker and cook on High for the first 2 hours, then set on Low for 4-5 hours.
However you cook the pork, it will be delicious!!
When the pork is finished cooking, use 2 forks to shred the meat. Keep warm in the IP or Slow Cooker.