How to Install a 2.5-inch SSD in the SSD Drive Bay of a 27-inch iMac Mid 2011 (Updated) - YouTube
Funky Cables and SSDs - The 27-inch Apple iMac Review (2011)
Amazon.com: OWC SSD Upgrade Kit for 2011 21.5-inch iMacs, Mercury Electra 250GB 6G SSD, 18" SATA III 6Gbps Data Cable, Installation Tools and iMac Screen Adhesive Tape Set : Electronics
OWC Internal SSD DIY Kit for Apple iMac 27" OWCDIDIM27SSD11 B&H