[Cabe]

Have a look at the front of the drive, is there a really small hole? If there is get a paperclip or something and unbend it and poke it in that button and press. Most drives have a feature like that to manually eject disks if (for example) the motor isn't working or the little drive chain has come off (that happened to me once)

If that doesn't work then chances are its physically jammed and will have to be taken appart