Cooking pulled pork in the oven typically takes around 1.5 to 2 hours per pound at a low temperature. Here's a general guideline for cooking pulled pork in the oven:

1. **Preparation**: Preheat your oven to 275°F (135°C).

2. **Seasoning**: Season the pork shoulder or pork butt with your desired dry rub or marinade. Allow the meat to marinate for at least 30 minutes to overnight in the refrigerator for maximum flavor.

3. **Roasting**: Place the seasoned pork shoulder or pork butt in a roasting pan or baking dish, fat side up. Cover the pan tightly with aluminum foil to trap moisture and prevent the meat from drying out.

4. **Cooking Time**: Calculate the cooking time based on the weight of the pork. As a general rule of thumb, plan for 1.5 to 2 hours of cooking time per pound of pork. For example, a 4-pound pork shoulder may take approximately 6 to 8 hours to cook.

5. **Internal Temperature**: Cook the pork until it reaches an internal temperature of at least 195°F (90°C) to 205°F (96°C). This temperature range ensures that the collagen and connective tissues in the meat break down, resulting in tender, easily shredded pulled pork.

6. **Resting**: Once the pork reaches the desired temperature, remove it from the oven and let it rest, covered with foil, for about 30 minutes to allow the juices to redistribute.

7. **Shredding**: Use two forks to shred the cooked pork into small pieces. The meat should be tender and easily fall apart.

8. **Serving**: Serve the pulled pork on sandwiches, tacos, salads, or as a main dish with your favorite barbecue sauce or other condiments.

By following these steps, you can achieve delicious, tender pulled pork cooked to perfection in the oven. Adjust the cooking time as needed based on the size and thickness of the pork shoulder or pork butt.