The folllowing assumes that you've at least glanced at the manual, specifically at pages 69-71 (if you haven't looked at the manual, I encourage you to do so).
Create a menu with the first graphic and the 2 buttons (a forward and reverse for example). Create a second menu that's a copy of the first one and change the graphic on the second menu to be what you want displayed when they navigate to the forward button on the first menu.
On the first menu, change the forward button properties: command to link, destination to be the second menu, auto activate to yes; optionally you can have the destination button be the button that they just navigated too.
On the second menu you will likely want to change the button properties to something that when they click enter will start playing the movie (or some such). Set the properties of the reverse button such that they will go back to the first menu when they navigate to that button.