Remove the door from the doorframe by tapping the hinge pins up out of the hinges with a nail and a hammer, then separating the two halves of the hinges.
Cut around the joint where the face trim meets the wall with a sharp utility knife. Some pieces of trim have caulking applied, others are painted and others are only connected to the wall with finish nails. Cut whatever caulking or paint connects the face trim to the ends of the baseboards where the two meet.
Pry the face trim off of both sides of the door frame with a claw hammer or a small crowbar, revealing the gap between the door frame and the rough opening.
Cut any nails that are connecting the doorframe to the rough opening by passing a reciprocating saw through the gap between the two and running it all the way around the door.
Pull the doorframe out of the rough opening. If it won't move, look for nails that you may have missed with the reciprocating saw.