How to mapping "Eject" key on Non-Mac keyboard?
One way you can eject a disk without remapping keys is to use the Eject Menu Extra item.
Just navigate to the /System/Library/CoreServices/Menu Extras/ folder and double-click on the Eject.menu file. It will put the 'eject' icon in the menu bar:

For me, this has worked for both internal and external drives. One click and the drive opens like magic!