I did my first cabin air filter change and it needed it. Have a shop vac ready, mine was filthy.
Here is a link from over in the hybrid forum that was helpful: http://fordcmaxhybri...bin-air-filter/
Basically you need a torx driver to remove one screw and that is it. The filter housing is located under passenger side dash, left side. There are two push pins (squeeze and pull) to remove the felt cover over the fuze panel. On your left you will see a single silver torx screw, remove it. Squeeze on each side of the filter door to remove. Pay attention to which way the filter faces when you pull it out. Be prepared scrunch up the new filter to squeeze it into the housing. All in all, the change took me about 15-minutes. Easy :)
Part number from box:
I ordered my filters from http://sunrisefordpa...m?siteid=217486, it's $13.50 and came with free shipping.
hope this helps someone.