Hi Friends, I'm wondering if its possible to install a new SSD on a late 2013 15" rMBP model? If so, how painful is it? How do you install the OS on it/move everything over from the old one (is it similar to windows?) I am looking to get a 15" soon, and trying to figure out if I should get the 256 GB and upgrade later if I need it, or just squeeze it out for the 512 SSD. Thanks!