Originally Posted by KiwiJochen

Here's the 'official' way to eject according to BMW:

For a CD that will not eject from the Navigation computer follow the procedure below:
1. Remove the Navigation computer.
2. Unplug the voltage supply (blue connector).
3. Reconnect the voltage supply and immediately press the eject button repeatedly until the CD in the drive is ejected.
4. Insert a new Navigation CD and restart the installation process.