MacBook Pro 13" Retina Display Early 2013 SSD Replacement - iFixit Repair Guide
128GB SSD Solid State Drive (SSD) 656-0021B for MacBook Pro 13" a1502 2015 Compatible Model: Macbook Air 13 "A1466, Macbook Pro Retina 13" A1502, Macbook Air 11 "A1465, Macbook Pro Retina 15"
Upgrading the new MacBook Pro is still a major pain
MacBook Pro 13" Retina Display Late 2013 SSD Replacement - iFixit Repair Guide