have you tried disconnecting the power from the Changer?
if that doesnt work..... you'll need to open it up (cd changer)
be very careful removing the 4 rubber pods b'cos they are what keeps your cd's from jumping/skipping and if you just look at all componants they do, just, (mostly), clip off. once youre inside and you'll see a small lever by the discs magazine, you can move the discs manually with this lever , take the discs out and re insert magazine (making sure its all right way round)
it may look difficult but you dont need to have an electronics degree to sort this problem.
p.s you may have to live with the fact that you could end up scratching that particular cd.
Hope this helps..
or try Audio and Mobile ltd its a Car Audio shop in maidenhead, 01628 633363
they'll charge you about 20 quid to sort it out, personally ive had 5 star service from them.
Good Luck.
Joseph
April 2007