How to turn rear DVD screen on from front

When you insert a new DVD into the front NAV, the rear DVD system starts displaying/playing it along with the front. That's fine. The next time you get in the car, however, the nav is playing the DVD and I can find no way to turn the rear screen back on for the kids without either using the remote or ejecting the disc. There must be an easier way!? 07 Yukon with nav radio and RSE. Any way to re-engage the rear screen without jumping through hoops like ejecting and reinserting the disc?

Thanks,
Mike