Playbill.com obtained the footage for you.
In the actual musical, based on the life of Founding Father Alexander Hamilton, Hamilton dies in a duel with rival Aaron Burr. But Armitage wrote a new, more conciliatory, ending to the show as a class assignment.
Armitage, who is a fan of Hamilton, got the revised script to author Miranda, who also plays the title role, and he performed it with co-star Leslie Odom Jr.
Here is the result: