If it's for presentation then, tie your butt as you would a boneless pork butt (or have your butcher do it). It will help to hold things together. Smoke it as you normally do and wrap it in plastic wrap and place it in the fridge. To reheat, take a roaster pan, put a wire rack in the bottom of the pan and place your tied butt on the rack (remove the plastic wrap) add any saved pork butt juices to the pan or pour some low fat/low sodium chicken broth (canned is fine) in the pan. Cover and seal with aluminum foil and place into a 350* oven reheat to an internal temp of 145-160*. Remove from pan to your platter cut the stings and begin pulling as usual. Add juices from the pan or use Finishing Sauce to keep the meat moist.