if you can get it out of the f/l then the only option is to open up the changer and there will be a release button on the body , may have a small round disc over it to stop dust etc . if the magazine wasn't full then this is why it jams. my alpine manwell says that the changer must be fully loaded with discs to avoid jamming and miss alinement.i have opened mine and boy there are loads of tiny springs and bits in there. took a while to get the cds back into the holders in there but now its fine.
good luck mate.