Trim the pork roast of excess fat. Combine the salsa, jalapenos, ground chipotle, brown sugar and beer in a large slow cooker. Place the pork roast in the salsa mixture and spoon some of the mixture on top of pork. Cover and cook on low for 8-10 hours.
When pork is done, remove any bones and use two forks to pull the pork, leaving it in the salsa mixture.
Warm the corn tortillas and fill with pulled pork. Add toppings as desired.