16 GB RAM Upgrade on MacBook Pro 15" (mid 2012) NON Retina - YouTube
MacBook Pro: How to remove or install memory - Apple Support
Adamanta 16GB (2x8GB) Apple Memory Upgrade DDR3L 1600MHz SODIMM Compatible for iMac (Mid 2011, Late 2012, Early/Late 2013, Late 2014, Mid 2015), MacBook Pro (Early/Late 2011, Mid 2012), Mac Mini at Amazon.com
Memory RAM Upgrades for MacBook Pro (2012 - Late 2016)