mine is driver side, back of radiator, just under the upper hose. removing the hose makes it a very easy job. and you can change you antifreeze while you are at it. Drain plug is below the thermofan switch at the bottom. I think I used a little teflon tape on the sensor....
you DON'T have to drain all the antifreeze out to change the thermofan sensor. But some will come out anyway....
If you do change the fluid, BE SURE to go easy on the drain plug and thermofan switch. especially if your radiator is original. the radiator end caps are made of fiber/plastic and the drain plug is made of plastic. Obviously, these become brittle with age and heat cycling. Or you could leave the drainplug in place and just undo the lower hose (drains much faster)
while you are doing this and the fluid is out, maybe change your thermostat and any hoses if needed. ALSO, check radiator endcaps for wear (against the surrounding metal frame)