This is included as a bonus feature on the 2006 DVD "Sesame Street: Old School - Volume 1".
Ironically, although Rowlf the Dog is the one pitching the show with the intention of being a feature character to a very reticent Kermit the Frog, Rowlf would subsequently appear in only one filmed sequences on the series proper while Kermit would become one of the major characters of the series.