Of course, I did try to tell him that I had actually taken out the interior sash(?) once already for cleaning - it has to be in the "top" of the window frame in order to be tilted out properly. But he insisted on cursing and looking at it puzzlingly for while. As of now, he's removed the interior pane, and now he's trying to figure out how to get the exterior pane - the one with the broken glass - out of the casing. -"Sash", "Casing", "Pane"... Yes, I know I'm probably using those terms interchangeably right now, but, frankly, I don't care.