WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
J 8763-B:
Holding Fixture and Base
Fig 1: J 8763-02 & Transmission
Courtesy of GENERAL MOTORS CORP.
Remove the transmission from the J 8763-B:
holding fixture.