Every instructional article or video I see always includes an outside corner, ie not a square room.

How would I install coped crown molding in a square room with 4 inside corners? My problem is that I think I would run into trouble with the last piece. If one end is butt and the other is coped how would you ever fit this piece in?

Would you leave the coped end of the next to last piece loose enough so that you could spring it enough to fit in the butt end of the last piece?