The pics shown at evilution site show the 3 tabs that make up the hinge of that access cover. The far edge, that closest to the firewall, are 2 tabs that can easily be pushed in to release the cover. It then hinges back towards you for an easy off. Makes more sense once you do it. It only took me a few seconds to open it up and pull the filter off
The owners manual states replacement at 10,000 miles/1 year. Most folks may only drive 10k a year. I do that every 5 months. I checked mine today and it was clean. Ill change it once a year or every 20,000 miles or so.
Good luck!