Has anyone tried the HD upgrade from OWC? I see they offer SSD upgrades for Retina macbook pros. I have a late 2012 128gig and I should have paid a bit more for a larger HD. Replacing the macbook with the latest release will not gain me much besides the HD space. So I am considering the upgrade. I have swapped out many HD's and RAM in the past. Super easy. But I have never opened up a Retina. I inquired about upgrading at a local Mac repair shop and they refused to do it. So my concern is - How fool proof is this OWC upgrade?