I found this cable very difficult to disconnect, be very careful because the cable is between a black tape and it's stuck very hard to the logic board and the cable is very short and you don't have space to move and separate it from the connection! Be patient and take the time you need

The central screw is very difficult to reach! Use a long and very thin T10 screw driver

What do you mean? I'm going to buy a ssd to add it in my imac 27 late 2013 the came without it.

Which part I need?