Amazon.com: MCE Technologies 1TB Internal SSD Flash Upgrade for MacBook Pro Retina (Mid 2012 - Early 2013) - Includes USB 3.0 Enclosure for Original Drive & Install Kit! : Electronics
How to Upgrade the SSD in a 15-inch MacBook Pro w/ Retina display (Mid 2012–Early 2013) on Vimeo
How to install an SSD on a 15-inch Retina MacBook Pro