Buick lucerne 2009 Owner's Manual page 169

To access the passenger compartment air filter, do the
following:
1. Press the tabs back and left to remove the cover.
2. Insert a tool behind the push pin located on the
inboard side of the air filter compartment to
carefully pry the pin out.
3. To remove the air filter, insert a tool between the air
filter and the compartment wall on the outboard side
of the vehicle. Then, push in to flatten the pin holding
the air filter in place. Gently remove the air filter and
any loose debris that may be inside the air filter
compartment.
3-31