Reenactment of History
One of the best ways of teaching history is by reenacting it. For example, rather than lecturing about a certain battle during the Civil War, a teacher may take the class to the place of combat for a reenactment of the conflict. This kind of learning tends to be more experiential, and thus more memorable.
The same teaching technique could be implemented in this lesson by reenacting the Council of Constance. Taking what Ellen White says about the council (see The Great Controversy, pp. 95, 104-112) and digging for additional details online, you can script a simple reenactment. Assign roles to your students and let them take the basic script and have fun with it. Chances are the students will remember this much better than if you simply lecture them about it.