CD player will not play?

I have a Ford 500- 2005 with a 6 CD changer in the dash,(factory installed from Ford) and the unit will not play or eject CDs. The unit trys to read disc, or trys to auto eject, but nothing happens. I am a mechanical person, put see no way of getting in to the unit, or any identification for the unit to look up a manual.
Can anyone help me???????