There is 2 filters stacked on top of each other. You have to drop down the glovebox from its frame by pushing in the 2 pins on the side of the glove box that hold the glove box in the frame. You basically have to crush the glove box together really hard to get them to clear the frame. Once you drop it you have to undo about 8 screws holding the frame in and allow it to fall, making sure you dont pull to glove box light wires when you drop it. Take off the trim side panel next to the left side of the glove box, it has 3 clips that have to be popped off by pulling it gently and one screw at the very top of the panel under the dash. This panel has one screw also under the glove box frame that has to be undone. Once you drop the whole glove box and frame there is a panel with a connector attached to it. Disconnect the connector and remove the panel by carefully removing 4 spring clips holding it on. After you remove the spring clips, dont pry them off in the center, the panel should slide down to remove it. The filters are stacked on top of eachother inside. They are in plastic frames.
I use to get the real filters from the dealer but they are pricey but do come with instructions. The filters are in plastic frames. Now I buy a fram fresh breeze for another type of car and make them myself. If you want to go this route buy the fram fresh breeze model number CF10140. Its big enough to be able to cut out the material to fit in the plastic frames from the factory filters. I have two sets of plastic frames so I just make another set and keep reusing the frames. Fram does make a fresh breeze for the 00-04 outbacks but they run about twice as much as making your own, but still cheaper and probably better than the factory filter. Stores usually wont carry these so you will have to order them online. Make sure you clean out the area with a vaccum before you install the new filters as lots of junk will get past them. If you make your own make sure the black carbon side of the fram filter is towards the a/c evaperator, which is the left side looking forward. Have this planned out before you cut them so you dont have to get another filter piece if you cut it backwards as the bottom filter frame is not square. The fram filter will have an arrow showing direction of airflow as far as what side goes where. the air moves from right to left in the airbox assembly when looking forward .
When you put it all back remember the glove box light will not come on unless the headlights are turned on so you dont think you messed up the light taking out the glovebox. Making your own with CF10140 is about 17 bucks, a real fresh breeze for the car is about 34 plus shipping to order it and a factory filter is in the 50 dollar range last time I checked. I like the fresh breeze because it has the carbon on it to reduce odors. The factory filter is just plain white, not very impressive.
Link to the CF10140 [ame]http://www.amazon.com/CF10140-Fresh-Breeze-Cabin-Filter/dp/B0010DW608[/ame]
