I would highly advise watching this youtube video for the software side of things. You CANNOT just replace the HDD on a stock system. It must at least be softmodded so that you can run software to clone the existing data and to set the HDD KEY.

https://youtu.be/yc_1KnqKr94

This video does a great job of covering the software side of things, as well as showing how to do this with a SATA drive.