MacBook Pro 2013 hard drive upgradable? - Ask Different
Amazon.com: 256GB SSD Hard Drive for Apple MacBook Pro Air 11" 13" 15" A1502 A1398 A1465 A1466 (Late 2013-2015) / OSX Sierra/Mac Pro A1481 : Electronics
How to upgrade SSD in late 2013 MacBook Pro with retina display - YouTube
MacBook Pro 15" Retina Display Late 2013 SSD Replacement - iFixit Repair Guide
Upgrading 2013/2014 Macbook Pro SSD to M.2 NVMe | MacRumors Forums