For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningHazard Warning Flashers
(Hazard Warning Flasher):
Press and momentarily hold this button on the instrument panel above the climate
control system, to make the front and rear turn signal lamps flash on and off. This
warns others that you are having trouble.
Press and momentarily hold again to turn the flashers off ...
Installation Procedure
Prepare all mating surfaces as necessary.
Align the front hinge pillar body reinforcement.
Drill 8 mm (5/16 in) for plug welding along the edges of the front hinge
pillar body as noted from the original
panel.
Clean and prepare the attaching surfaces for welding.
...
Strut, Strut Component, or Spring Replacement
Special Tools
CH-6068 Spring Tensioner Device
CH-6066 Holding Device
For equivalent regional tools, refer to Special Tools.
Disassembly Procedure
Remove the strut assembly. Refer to Strut Assembly
Replacement.
Install the strut to the CH-6066 holder (5).
Tens ...