I changed my air filter to a K&N last year and it's a very simple job. The air filter housing is at the front right of the engine bay as you look at it, and there are just 4 or 5 screws (can't remember exactly) to undo to be able to lift off the top and remove the old one. The new K&N dropped in perfectly.
If you look in the Idle Chit Chat section of this forum you'll find a thread regarding K&N filters with some links to the filters others have purchased. I got mine from Amazon at a reasonable price.