It sounds like you need to visit the
Jedi Training Academy! Located in Hollywood Studios near the Star Tours attraction, this exciting live show will be just what your grandson needs to learn the secrets of The Force. About 10-15 children are selected to participate in the show, too, so I suggest you arrive early to get a spot up front, and encourage him to be an enthusiastic volunteer!
There are fun rides and attractions featuring Dinosaurs in Animal Kingdom, and Toy Story rides in both Hollywood Studios and Magic Kingdom, as well as a walk-through photo-op with every scene from the Toy Story movie!
Beyond that, I'm afraid you won't find a special 'makeover' in one of those themes. You can certainly create your own, though, by having his face painted in the parks, or visiting the Harmony Barber Shop in Magic Kingdom for a colored gel and sparkles Mickey Mouse hairdo (yes, this is for boys!)
Have a wonderful vacation!