Hi John it's difficult to say, how is the door ill fitting? If the gap around the door is too small and the door is catching it's a matter of planing the door until you have a gap of around 2-3mm around the door, on the latch edge of the door allow a slight bevel ( leading edge) to give more clearance when the door swings towards the frame. There may not be enough gap between the door and the frame ( hinge bound) either pack the hinges or remove the hinges and plane the door to give more clearance. You-tube is good for demonstration videos if you want more tips or post your job on Rated People. Thanks. Ed.