I want to replace the HD in my Mid 2011 27" i5 iMac with an SSD. All I want to do is replace the current drive not add a second drive. All the guides seem to be about adding a second drive. I don't want the noisy drive that's in there which is just stupidly slow these days. So my question is what do I need? I want to add a 512GB Crucial m4 2.5-inch SATA 6GB/s What else do I need? Do I need the cable people seem to be buying on Amazon?