I've got a new to me 2006 950 Adventure S that appears to be leaking a bit of oil from the gear position sensor. The parts manual for the engine shows an o-ring behind the sensor. Is this something that could be replaced pretty easily during an oil change by pulling the sensor out and putting in a new o-ring? Is the sensor plugged into or attached to anything in the transmission? How does it "sense" gear position? Magnetic? Electronic? Optical?