Hi Steven, try Option + Eject, if jumpers are set to Cable Select that should work.
Might be Option + F12 if you don't have an Eject key.
# In the Finder, choose Customize Toolbar from the View menu. In the window that appears, drag the Eject button to the toolbar, then click the Done button. After following these steps, the Eject button will appear in a Finder window toolbar—in the Finder window, select the disc you want to eject and click the Eject button in the toolbar.
# Click the eject button in iTunes.
# Use the Eject menu bar item. If the computer has two optical drives installed, you will be given a choice of which drive to open.
To show this menu bar item:
1. From the Finder's Go menu, choose Go to Folder.
2. Type or paste: /System/Library/CoreServices/Menu Extras
3. In the Menu Extras folder, double-click "Eject.menu".
http://support.apple.com/kb/HT2575