I have a 2012 mbp which I purchased in January and did not know much about the differences of the hard drives. I just purchased a Samsung 850 Pro SSD - my question is can I download a copy of Mavericks from the App Store to an external hard drive, then swap out my current hard drive with the SSD and then install the OS from my external drive? Will that work? I don't have much on my computer so I don't mind just doing a fresh install of the OS. I don't really care to clone the hard drive. Thanks in advance for your help.