WARNING: This page is about a different car, the 2016 GMC Acadia, 2016 Chevrolet Traverse, and 2016 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Rear Seat Head Restraint (With 40% Seat)
Courtesy of GENERAL MOTORS COMPANY
Callout
Component Name
1
Rear Seat Head Restraint Procedure Insert a small rounded tool into the hole in the head restraint guide to release the lock tabs while lifting upward on the head restraint to remove.