If you have a package, all you have to do is call and ask to apply the promotion. If the resort and room type you booked is not available for the promotion, you'll have to switch resorts or room types, and they'll help you do that. As an example, Little Mermaid rooms at AoA are exempted from free dining, so if you booked a room there and would rather have the dining than the resort, they'd help you switch to, say, Pop Century.