An Aspect Ratio Change within a movie?

Um, Excuse me, How can I change an aspect ratio like 1.85:1 to another aspect ratio like 2.35:1 in one of my movies? How Can I open one of my movies in 1.85:1 Academy Flat and after the first half hour or first few moments or so, change the ratio to 2.35:1 CinemaScope? How can I do it?An Aspect Ratio Change within a movie?yes yes a film school will let you know yes