Teardown of New 21.5-inch iMac Reveals Glued Down LCD and Dual Microphones - MacRumors
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
iMac Pro Memory Maxxer RAM Upgrade Kit
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
iMac Intel 21.5" EMC 2544 Repair - iFixit
How To Upgrade RAM on the Apple iMac 2012 - 2013 RAM Upgrade - 21.5 inch model - YouTube
What Does It Take To Upgrade a 2012 iMac 21.5"?
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
OWC 8GB (2 x 4GB) PC12800 DDR3L 1600MHz SO-DIMMs Memory Compatible with 2011-2015 iMac, 2011-12 Mac Mini, and 2011-2012 MacBook Pro (Non-Retina Display) Models (OWC1600DDR3S08S) at Amazon.com
CMS 32GB (4X8GB) DDR3 12800 1600MHz Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Retina 5K 27-Inch (Late 2014) Core I5/I7 - A6 at Amazon.com