I will begin applying vinyl to my house soon and I plan on also re-sheathing most of it. Most of the current sheathing is that pressed cellulose blackboard ( celotex ) garbage. The house has some older windows I would like to save. What is the best way of removing / replacing the sheathing with out disturbing the windows ? Is it better to cut the celotex out around the brick mold applied to window and refit sheathing, or carefully pry off old brick mold on window and remove all the celotex ?