It is very frustrating when your 6-disc CD player freezes or gets jammed and refuses to eject the discs. This normally happens when your player gets too old or the disc lens acquires dust from outside. There isn't one single solution to this problem. Rather, there are a list of things you can do to to fix it.
Straighten up a paper clip and use the sharp pointed edge to push a tiny hole located next to the tray that mounts your discs. This is your emergency eject button. The 6-disc CD changer tray should open immediately when you push this emergency button. If the emergency eject option doesn't work, follow Step 2.
Unplug your CD player. If it's a car stereo, turn off your car engine. Wait for at least 10 to 15 minutes before you plug it back in. Push the regular eject button and see if the CD tray opens up. If this doesn't work, follow Step 3.
Find a blank disc or a disc that you don't use anymore. Insert this disc about an inch deep into the slot where the discs go in. This step will not work for audio players that use trays to mount discs. Now, move the disc gently sideways while pushing the eject button repeatedly until the discs come out. If this doesn't work, follow Step 4.
Contact the manufacturer if the CD player is still under warranty. Remember, if you try to open the player, you will be voiding its manufacturer's warranty.
Take the CD player to a repair shop if it's not under any warranty. You may have to replace the motor that ejects the discs.
If your CD player is more than 6 years old, you may want to replace it with a new one. Doing so may be cheaper than repairing it.