Coolant Temp Sensor

[alex.mcintosh]

I've got an A4 B8 2008 2.0 TDI and the temp gauge always used to read 90. A few months ago it started to fluctuate between 80 and 90 and now it is between 60 and 70. I'm going to check out the thermostat, but in case it's the coolant temp sensor, does anyone know where it is located and how easy it is to replace? I'm going to France in 10 days time and don't want any issues....

Thanks