For a more in-depth look at this video, check out the accompanying article on THISisCarpentry.com -- http://www.thisiscarpentry.com/2016/09/09/installing-a-pair-of-doors/
And don't forget about Gary's DVD programs on Mastering Finish Carpentry. You'll find more information about the Doorhanger's DVD on his website at garymkatz.com/shop