Currently Being ModeratedDec 6, 2012 10:14 AM (in response to deborahstonesifer)
First, you should "unmount" the loaded drive from the operating system. You can do this in Finder, or you can Command-Click the desktop icon and select "Eject". Wait for the icon to disappear from Finder or the desktop, then simple pull the SD card from the slot.
To unmount/eject the drive in Finder, scoll to the drive in the left shaded collumn of a finder window, until you locate the drive uner the heading, "devices". Then click the tiny eject icon to the right of the drive listing.