I had the same problem with mine some years ago. I got Shirl to press the eject button while I gently tapped the CD changer and eventually it popped out.
I had the same thing with my Z4 which houses the changer in the rear section behind the centre console. I got it the same way, although I did have to be a bit "forceful" with the "tapping". The 2nd time it happened I cleaned the back of the disc cartridge and sprayed it with silicone spray and it has been fine since. So, if you get it out Paul I would try that.
Tony.
ps. I also burned copies of the original discs and put them in the changer, ...... just in case.
