You remove the cover under the passenger footwell by removing 2 screws and bringing the cover down gently. The 12v acc socket is in the cover too so be careful. Next, there is a filter cover to remove under the cover you just removed. The filter cover comes down after pushing a tab (towards the rear of the car?) that releases the cover. Then, you pull the filter down and out.

There are better instructions on the board here that you can search for but it is a 5 minute job that will cost about $20 for the filter. Airflow is from the door to the center console.
Joe