WARNING: This page is about a different car, the 2015 Chevrolet Trax and 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Water Outlet, Bolts And Seal Ring
Courtesy of GENERAL MOTORS COMPANY
Remove the 3 water outlet bolts (3).
Remove the water outlet (2) and the water outlet seal ring (1).