I was able to leave mine in the car and adjust... a long philips screwdriver reaches down there and you're able to teeth on the gear engage the screwdriver. However it's SLOW going as the adjustments are fine and if you're not holding the screwdriver just right you'll just slip it on by... I find I needed to apply some sideways tension when I did it in order to keep the screwdriver engaged.
If you look in your picture, at the top of the wheel are two plastic tabs... the screwdriver fits right between them.
EvilEagle - "Imaguy3 just made everyone in this thread his *****."