Make it into a celebration like the Jews do. Wikipedia http://en.wikipedia.org/wiki/Purim gives a lot of great information about the celebration. It also explains how it is celebrated and some good cookies (Hamantaschen) that are part of the celebration.
The main part of the celebration is an interactive reading of the story of Esther called the Megillah. You can do this by simply assigning parts for Esther, Mordecai, Haman, Wife of Haman, King Ahasuerus, Memucan (the king’s councilor), crowds, and you as the narrator. Often they will dress up for this. The audience will also use noise makers to drown out the name of Haman (the villain) every time it is said.
With all the fun, make sure your class doesn’t miss the powerful principles in Esther 4:14. The lesson manual teaches this well and I also like the following quote: “To every man there comes in his lifetime that special moment when he is figuratively tapped on the shoulder and offered the chance to do a very special thing, unique to him and fitted to his talent; what a tragedy if that moment finds him unprepared or unqualified for the work which would be his finest hour.” – Winston Churchill.