You can put a fresh install of an OS on the SSD and transfer all the data on the HDD via SATA - USB adapter, or separate external hard drive. After that, you can format the data drive, put all the other things back on it, and you're good to go. I will assume you are using Windows, since you didn't mention it. You will go to My Computer and it will show 2 separate drives, along with disc drive, and any other drive plugged in, etc. If your computer defaults to downloading items on the wrong drive, I will refer you to this article. --> http://www.tomshardware.com/forum/15860-63-make-drive-default-install-point
Hope I answered your questions!