There is a plastic door that covers the filter. It has 2 clips, one on the top and one on the bottom. Just unclip it and remove it. You'll see the filter now.
When it's all cleaned out, slide the new filter in. Make sure you get the filter in correctly. There are arrows showing which way the air flow for the filter goes and the outer box that the filter goes in shows arrows for the airflow there also. Just match them up and your good.
Install the metal brace with the 2 screws and 2 bolts. The bolts (gold ones) go on the inner holes and the screws (black ones) in the outer holes.
Tomorrow I will post the procedure for changing the transmission fluid and filter on a Honda Odyssey. I did that today also and took lots of pictures so it should be a decent post. I will also show the filter I took off the van and what I found inside it. (I cut it open and inspected it). See you then!