How to Upgrade Memory in a 21.5-inch or 27-inch iMac (Mid 2010) - YouTube
Install memory in an iMac - Apple Support
NEMIX RAM 32GB (4x8GB Upgrade) DDR3-1333 PC3-10600 204-Pin SODIMM Memory for Apple MacBook Pro Early/Late 2011, iMac Mid 2010 27 inch 4-Core, iMac Mid 2011 21.5/27” , Mac Mini Mid 2011 at Amazon.com
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
iMac 27 RAM memory upgrade Easy How To Tutorial Mid 2011 - YouTube
Upgrade your iMac's RAM in less than 5 minutes - YouTube
How to upgrade RAM on iMac 21.5" 2011 - YouTube
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
21.5” mid-2011 iMac wires? Finally trying to upgrade my RAM and these wires are blocking the slot — did get an iMac with poor build quality? What can I do? : r/mac