My battery completely died and left me with the e-02 and e-01 situation after replacing with a new battery.
So, I found this thread and tried without success to use that button to eject the CD. By the way, its mechanically spring loaded so you don't need power to the unit while sliding in the credit card on the lower edge of the magazine.
You'll see a metallic looking tab about 1/4" in width centered under the bottom edge of the changer. Basically you need to simply push in that credit card (now taped to the changer for future use) no more than 2 inches to disengage the mechanical hold.
But, in my case, it was not releasing so I investigated further with a flashlight and noticed a CD halfway between the magazine and the player. Nothing I tried was going to move that CD in or out.
So I found a 1/16" thick 6" long metal ruler to basically and carefully push the cd back into the changer. This allowed the mechanical credit card trick to release the changer. Once this was done I was still unable to electrically eject the CD so I just pried it out since it was fairly accessible.
Next step, connect power, put the ignition key in, turned on the radio/cd player and put in an empty magazine where it cycled and found nothing to play. Pressed eject and loaded it up and its all up and running again.
Thanks for the tips!
Also found this which helped explain the location of the switch a little too.
http://forums.prod.legend.org/audio/msgs/1661.phtml
What a terrible design on Alpine's part that allows this to happen! Geez!