Upgrading Ram in a Macbook Pro 13" | How to Upgrade Ram on 13" Macbook Pro - YouTube
Apple MacBook Pro 15" Retina 2.4GHz 8GB Ram Logic Board Early 2013 820-3332 for sale online | eBay
A-Tech 16GB Kit (2x8GB) RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
MacBook Pro 15" Retina Display Late 2013 Teardown - iFixit
MacBook Pro: How to remove or install memory - Apple Support
MacBook Pro 13" Retina Display Early 2013 SSD Replacement - iFixit Repair Guide
A-Tech 8GB RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
How to Upgrade MacBook Pro RAM (2009, 2010, 2011, 2012): EveryMac.com