I loved this ad when I first saw it. It was so well done i wanted to see what the original footage looked like and how much they did it. Let me be the first to say this is amazing, so seamless.
Created by: The Mill
Video Info (via FxGuide.com):
In this NFL spot, directed by Ryan Mckenna and Ben Smith for Grey NY, The Mill substituted items of clothing on characters from beloved sit-coms like Happy Days and Seinfeld with Super Bowl themed attire. New elements were filmed with a mix/overlay system on set, with that footage altered to match the resolution of the existing material. The final shots composites involved meticulous work to match character and cloth movement.