I upgraded my 2012 2.4GHz Quad-Core Intel i7 from a 1Tb 5400rpm drive to a 1Tb SSD. This guide made the upgrade very straightforward, and I am very happy with the results. I used the drive and cable from OWC and the difference in speed is night and day!

I used the guide to replace the original 250 Gb hard drive with a SSD. Worked great! While in there I replaced the CR2032 because why not. The guide was thorough and made a big difference to me as I had never disassembled this Apple iMac before. Thank you!