Mark Lovick, creator of Watch Repair Talk, has just put up a three-part (+ bonus) video tutorial showing him servicing a 7S26-0020:
Assembly: Gear train
Assembly: Motion work & calendar
Extra: Removing mainspring from barrel
They're in his usual clear style and easy to follow...
To encourage everyone here, I took pictures while doing my first crystal replacement. I have no experience with this, so maybe I overlooked some things - please reply with notes on how to improve my process.
This "tutorial" is also available as an album on imgur: http://imgur.com/a/GnFY0