2. Much like the back window, the windshield opening will stay the same size; the sheetmetal needs to be dissected so the roof can be removed, leaving just the windshield opening. John has done this type of thing for years, so he knows where to start. He makes identical marks on both sides of the roof where it will be removed from the A-pillars. John states, "This is determined by where the horizontal portion of the roof starts to curve down to the A-pillar. The vertical mark should be made at the end of this horizontal portion, just before the curve." This line will be transferred to the door frame to provide the front cut line on the door.