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:
When Iain Loves Theatre rewrote a "nicer ending" to Hamilton the Musical for a school assignment, we had to try it out!
Posted by Hamilton the Musical on Tuesday, July 7, 2015
Hamilton begins previews at Broadway's Richard Rodgers Theatre July 13.
Armitage's videos can be seen on the Iain Loves Theatre Youtube channel.