WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
Unlock the quick fitting (1).
Remove the auxiliary water pump outlet hose clamp (4).
Remove the auxiliary water pump outlet hose (5) from the auxiliary water pump (3) and from the water outlet housing (2).