All you have to do now is install it. It's not hard at all. Read the drive's manual to familiarize yourself with what you're about to do. Any installation techniques particular to your drive will be in the manual. This page serves only as a general outline.
Installation Make sure the computer is turned off.
Unplug it and disconnect it from the wall outlet. Remove the cover from the drive bay in which you want to install the drive. This is done by taking the case off and pushing the tabs that hold it in place toward the center of the computer so that they are no longer holding it. Next, remove the drive from the wrapper, and adjust the jumpers on the back of the drive according to the manual. Most drives come with the most common setup already configured with the jumpers, but you may want to double check or change the settings for your situation.