Adding onto Abby, place your inside leg a bit in front, in order to support his shoulder. You can practice using figure 8s, and asking for the simple change. Your horse will eventually pick up and understand what you Andre asking if you Andres like Abby said above in your simple change.
Hi Ana, I'm not quiet sure waht you mean by breaking, but in order to do a flying change, you simply give the aid to pick up the other lead (sit and use outside leg behind girth). But the horse must be trained in this aid to understand it. Hipe this help 👍