Not sure if this helps much, but my Haynes says "On petrol engines, the thermostat is fitted to a distribution housing on the left hand side of the cylinder block, behind the coolant pump position" . Depending on the engine code, there seems to be varying degree of dismantling to get to it.
The coolant temp sensor info is "On all models, an engine coolant temp sensor is located at the rear of the cylinder head, whilst on some engines, a second sensor is fitted to the radiator outlet pipe".
Mike.