I have the iMac i7 bto late 2009 model with the 1tb hard drive. WIth the new air out, I've been considering the advantages of ssd storage. So I'm contemplating upgrading my iMac's hard drive and replacing the 1tb with an ssd model and using the 1tb as external storage. Is this possible? Is this difficult for me to do myself? If so, is it something a third party or Apple Genius could install? Is it even worth it?