Ever wonder how MacPro eject 2 optical drive?
Doesn't have second optical drive to try out? Here's a trick that might work for you.

1) Makesure you have a DVD image or CD image.
2) Mount it.
3) Launch Activity Monitor.
4) Look for progress name "SystemUIServer" and quit or force quit it.
5) You will see the eject button once the menu reloaded if successful.
6) Press command + drag the eject icon to change it's location.

Updates:
It appear that there's a simpler way round, navigate to - System/Library/CoreServices/Menu Extras/
Double clicking on the item(s) will put it in the menu bar.
(thanks new2mac from mymug for the tips)

here's how it looks like:



Does my guide works for you? do let me know