Yesterday, I tried to open the trunk and only the driver side buttress released. No amount of tugging would free the passenger side. Since the trunk wouldn't fully open that also meant I couldn't fully close it. So I had to drive home with the trunk open chime sounding the whole time. Ugh.
I read that a tool was made specifically for releasing a stuck buttress, however I absolutely did NOT need it. I inserted a small allen wrench into the inboard side of the buttress retaining hole and clamped a pair of vice grips on the end for extra pulling leverage. Pulling toward the center of the trunk lid I got the buttress to release no problem.
Pic of where I inserted the allen wrench:
Pic of the passenger side buttress retaining pin and which way it needs to be pulled to release the buttress:
Next, I removed the multitude of plastic trunk lid liner retaining clips and set the liner aside. Pic shows the buttress release actuator cable and the access port for the passenger side actuator assembly:
This pic shows the driver side buttress actuator:
Arrows mark the two nuts that secure the assembly to the mounting studs on the trunk lid. The circled portion shows how the release cable attaches to the end of the retaining pin. What happens is that orange plastic piece breaks off leaving only the metal ball tip of the cable. The diameter of the metal ball tip is smaller the the j-shaped loop end of the retaining pin. With that orange plastic piece broken off I could push the trunk release button and watch the ball end of the cable slip through the loop end of the retaining pin without pulling it inward (to release the buttress).
Pic of the broken passenger side actuator:
What I did was remove the two nuts holding the actuator assembly to the lid, routed the actuator cable and ball end back through the loop end of the retaining pin, and used channel locks to pinch the loop end of the retaining pin closed to decrease the diameter of the opening. Pic of the finished product:
Now, the ball end of the cable pulls against loop end of the retaining pin and everything works normally again.