Buick 2002 Park Avenue Owner's Manual page 311

3. Push the tab on the wiper blade assembly and pull
the assembly down enough to release it from the "U"
hooked end of the wiper arm. Slide the assembly
away from the arm.
4. Replace the blade.
5. To reinstall the wiper blade assembly, slide it over
the wiper arm to engage the "U" hooked end on the
wiper blade assembly. Pull up on the assembly to
lock it into place.
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