Got it! - I was able to strip all security from the PDF file. I don't know why these people bother.
The bottom of the sensor has a small reservoir
with two small holes underneath to let the oil enter
inside and one at the top to let the air enter
allowing the oil to flow out.
When there is enough oil inside the oil tank (and
therefore in the sensor reservoir), the sensor detects
the liquid and the light DOES NOT turn on.
When the oil level goes at critical LOW level inside
the oil tank (and therefore in sensor reservoir), the
sensor detects the absence of liquid and the light
TURNS ON.
To check the oil sensor, unplug its connector and
pull sensor out of oil tank.
Using a multimeter, check the continuity between
the BLUE and BLUE/BLACK terminals.
When sensor is out of oil tank and its reservoir is
empty, resistance must be infinite (open circuit).
NOTE: Wait about 15 - 20 seconds before taking
any reading to give the oil enough time to flow out
or inside sensor reservoir.
Soak sensor in oil so that its reservoir fills up. Maximum
resistance should be approximately 2 Ω
(closed circuit).
And yes, to remove the air box on the 97+ XP, it is much simpler to remove the oil tank first. You don't have to pull the lines, just the sensor wire connector. them move the oil tank out of the way... makes getting the box and then engine if needed 100x easier. Also on the GTX, I'm not sure you have to, but removing the 4 bolt seat support makes getting that air box out 10x easier as well.