How to Eject Disks from Your Mac Running Mountain Lion
Ejecting a disk from your Mac, whether it's running OS X Mountain Lion or earlier versions of OS X, is a piece of cake actually. Here are several ways, all simple to remember:
Click the disk’s icon to select it and choose File→Eject (or use the keyboard shortcut Command+E).
Drag the disk’s icon to the Trash. When you drag a disk’s icon, the Trash icon in the Dock changes into an Eject icon, like the one shown in the left margin.
The preceding method of ejecting a disk is something that used to drive me (and many others) crazy before OS X. In the olden days, the Trash icon didn’t change into an Eject icon. This confused many new users, who would ask the same question (over and over and over): But doesn’t dragging something to the Trash erase it from your disk?
This technique does something completely different if you’ve dragged any files onto the disc. In that case, the Trash icon turns into the radioactive symbol, and your Mac offers to burn the disc. Put another way, this ejection technique works only if the disc is blank, has already been burned, or is a store-bought prerecorded (read-only) CD or DVD.
Click the little Eject icon to the right of the disc’s name in the Sidebar.
Press the Eject key on your keyboard if it has one. (If it has one, it probably has the Eject icon on it.)
If your keyboard doesn’t have an Eject key, press the F12 key, and continue to hold it down for a second or two. On many keyboards that don’t have an Eject key, this keyboard shortcut ejects a disc.
Right-click or Control-click the disk icon and choose Eject from the contextual menu.
There’s one more way, if you like little menus on the right side of your menu bar. To install your own Eject menu on the menu bar, navigate to System/Library/CoreServices/MenuExtras, and then open (double-click) the Eject.menu icon.
Your Eject menu appears on the right side of your menu bar. If you get tired of the icon on your menu bar, just press Command and drag it off, and it disappears with a satisfying poof.