You need to unscrew the outer metal bracket in order to free the hard drive. From the picture, you can see two screws on left left side of the picture. Also unscrew the two on the right.
After you have freed up the harddrive you can either buy a harddrive enclosure at a place like NCIX. Or you can plug the harddrive into your desktop computer if you have one via sata cable and power cable.
It should look like this after you have removed the bracket:
