New MacBook Pro makes DIY upgrades and repairs tough
MacBook Pro: How to remove or install memory - Apple Support
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
OFFTEK 4GB Replacement Memory RAM Upgrade for Apple MacBook Pro 2.5GHz Intel Core i5 - (13-inch) (DDR3) (Mid-2012) (DDR3-12800) Laptop Memory at Amazon.com
Does the mid-2012 13 MacBook Pro have an M.2 slot that I can use for an Intel Optane memory upgrade? - Quora
Mid-2012 Macbook Pro 16GB RAM Upgrade How To - YouTube
upgrade - 32gb of RAM on a 2011 or 2012 15/17-inch MacBook Pro using Crucial's 16gb single DIMMs - Ask Different