I have removed the back of the freezer by taking out 6 screws, and exposing the fan.
I can see both the yellow and green plugs for both thermistors, and see the green thermistor itself just below fan.
I have also taken out the 2 screws holding the fan housingto loosen and remove the polystyrene, but HOW DO YOU REMOVE THE THIN STEEL PLATE TO BE ABLE TO GET TO THE OTHER THERMISTOR?

GARRY ASHWORTH, December 2005

I wrote this for another forum - have just copied it here. First off put the screws back that hold the fan in place then take a look at the text below - hope it helps.
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I am not an engineer but here's a spot of advice that would have helped me out during the fitting of the evap thermistor. Assuming all FF92s are the same:

With the power off, remove the internal housing at back of freezer compartment (8 screws). You then need to wriggle out the polystyrene panel (that holds the freezer thermistor) and then you are presented with an aluminium panel that covers the evaporator. You need to get this out of the way to get to the evap thermistor. TAKE CARE This panel is connected to a series of reasonably delicate electrical stuff (told you I wasn't an engineer!) which is essentially fixed to the back of this panel and the wires are threaded through various loops in the evaporator. Also if you have any ice build up then all of the above wires could be enased in ice. Thaw it out (if required) then move the aluminium panel as if you are opening a door towards you with it hinged on the right hand side - that way you shouldn't damage any of those wires. Then you can leave the wires connected and prop up the aluminium panel while you change the evap thermistor.

Hope this helps

Doug, December 2005