First, you must remove the windshield wipers to allow removal
of the "false-bulkhead".   Use a 13mm rachet.  There is a plastic
cap over the bolt that must be gently lifted up.  This can be difficult
since dirt can cause it to be stuck.

After both windshield wipers are removed, the false bulkhead
can be removed.  Before removing the false bulkhead a black
rubber strip just in front of the false bulkhead must be removed.
This can be removed easily by hand.  Then the false bulkhead
can be removed; it is fragile, so do not pry it or use force.
It is held in the rubber strip on the windshield and the rubber strip
you have just removed.

Once the false bulkhead is removed, the cabin air filter can be
easily replaced.  Note that the cabin air filter has a special key
on the side to assure that it inserted correctly.