Have you ever tried to unmount a disc in Mac OS X, but it simply wouldn't come out of your Mac's drive? Here are three ways of removing discs from your Mac's drive. If your Mac is currently using the disc you won't be able to eject it, so make sure that isn't the case first. If the disc isn't in use and you still can't eject it, give these a try.
Step 1: Drag the disc to the trash can
Find the disc on the desktop and drag its icon to the Mac OS X trash can. As you start dragging it towards the trash, the icon will change to an eject button, release the mouse button when the disc's icon is directly over the eject button.
Step 2: Try some command line goodness
If you have tried to eject the disc by dragging its icon over the trash bin, then why not try a simple Terminal command to eject the disc. Open Terminal.app (found in /Applications/Utilities/Terminal.app; or use Command + Shift + U to in any Finder window to move to the Utilities folder).
Once you have Terminal opened, type (or copy/paste) the following command: drutil eject
Step 3: Restart your Mac while holding mouse button down
If you've tried the other steps to no avail, then why not reboot your Mac while holding down the mouse button. Upon loading the Apple boot screen, your disc should be ejected.
Please note that if you have a disc that is actually physically stuck in the drive, this will not help. Stuck discs may need the assistance of an Apple Genius or certified Apple repair professional.