How to Upgrade the 3.5-inch Main Drive in a 21.5-inch iMac Mid 2010 (Updated) - YouTube
27” Mid 2010 iMac Disassembled
Apple iMac 27-inch (July 2010) review: Apple iMac 27-inch (July 2010) - CNET
Installing additional SSD in Mid-2010 27" iMac
Apple iMac 2010 (Mid) 21.5-inch (iMac 11,2) SSD ,Ram & OSX Upgrades - ZD Laptop Service Centre
iMac 27" 21.5" 480GB-1TB SSD Upgrade Service 2010 - 2019 Inc Data Migration | eBay
2nd SSD HDD Hard Drive Tray Caddy for 27" 21.5 iMac mid late 2009 2010 2011 2012 | eBay
Amazon.com: 2nd HDD SSD Hard Drive Caddy for Apple iMac Mid-2010 A1311 MC508LL/A MC509LL/A MC508 MC509 21.5-Inch Desktop Computer, SATA 3 Second Solid State Drive Enclosure, CD DVD SuperDrive Optical Bay :
Installing additional SSD in Mid-2010 27" iMac
Amazon.com: OWC/Other World Computing Internal SSD DIY Kit for Apple 27" iMac 2010 Models : Electronics
What you can do with an internal SSD module from a vintage Mac | Macworld
Upgrade Sata HD to SSD on a iMac 11.3 27" mid 2010 | MacRumors Forums