I have been pondering the idea of which hard drive to replace my old Macbook Pro (mid-2009)'s hard drive. So I went with the Seagate Momentus. I got it and was looking around and realized there was no way to format it. Do I need to buy an Adapter for it. Or do I need my install disk (which I do not have, but have a iMac Disk)? Can I just plug it in?