You have to remove the door panels. Good thing your changing speakers, you can do this while you have the panels off. Make sure you get all the screws, they're tricky (one kinda behind the door-opener-lever, two behind the front door handles, and a bunch around the edges of the door panels). You'll have to use a utility knife or razor blade to cut the silicone/caulking that seals the foam to the door to get to the little green light bulbs. They're mounted into the black frame of the door-opener-lever assembly (I know, real technical terms

). Order a few extra of the little green light bulbs from Bill Jenkins, or fordpartsonline.com until Bill gets back. Have fun!
BTW, the new green ones will be a slightly darker green compared to the old ones. That's normal, its just fade. If it really bugs ya, replace the other bulbs too while your doing your speakers.