Rose,
The links to these episodes work.
The links in the above reply are from before Mobility Wod updated to The Ready State.
Go to Search the Archive on the Virtual Mobility Coach and enter the episode name for the updated links.

Episode 15: You Must Defeat The Evil Chair Part 1
Episode 15: You Must Defeat The Evil Chair Part 2

Episode 88: Desk Athlete Hip Rescue
Episode 91: Mobilize In the Position of Death by Chair
Episode 187: Death by Chair. How Much Do Actually Sit?
Episode 276: MobilityWod Google Talk: Desk Bound
Why Sitting Wrecks Your Mad Hip Action

You can do a search on the Virtual Mobility Coach archive for other episodes which address sitting.
Read descriptions of the daily mobility episodes or check out the down regulation episodes on the app.