Mid-2012 15" MacBook Pro Retina - upgrading to Big Sur? : r/BigSurPatcher
How To] Upgrade RAM In A 2012 MacBook Pro - YouTube
Memory RAM Upgrades for MacBook Pro (2012 - Late 2016)
New MacBook Pro makes DIY upgrades and repairs tough
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com