I thought it would be a good idea to open up my iMac and found out it wasn't going to be easy with no mounting hardware where it was supposed to be.
The nice folks at foxcon either forgot to put in the mounting hardware for the ssd or Apple decided not to give you the option to put your own in. Opened it up and was disappointed. Put it all back together then my iMac would shut of every 20 or so minutes and that's when I realized I missed the connector for the Optical drive fan.
I would help to do more research than I did. Although my iMac was supposed to be the only model that came with the hardware for a SSD, there was none to be found.
Metal Spudger Set
Heavy-Duty Suction Cups (Pair)
Mako Driver Kit - 64 Precision Bits