Here's how to take it apart, some of which is destructive.
1. Here's the sensor as it comes off the bike.
2. It's possible to remove or grind off the center pivot and remove the rotating contact holder. That's described here
and gives you access to the contacts.
3. Here's the other side. There are resistors potted in (I think) white silicone rubber.
4. It's possible to remove the silicone revealing the resistors.
Gasoline causes silicone to swell/weaken, which makes removal easier.
5. At that point, the resistor resistances can be measured, which is what I'm interested in. The color bands can also be noted, though I've tried on those in the picture and the resolution isn't good enough to get values that make sense. It's also possible to measure things through the contacts on the other side but you need to know what you're doing there. The resistances are something
like 370, 825, 1500, 2800, 6100, and 15000 ohms. The corresponding color bands for those resistances are Or-V-B-B, Gy-R-Gn-B, Br-Gn-B-Br, R-Gy-B-Br, Bl-Br-B-Br, and Br-Gn-B-R, where R=red, Or=orange, Gy=grey, Gn=green, Bl=blue, V=vilot, Gy=grey, Br=brown, and B=black. But that's mainly not what's in the picture. There will probably also be a fifth band that is Br and not of particular interest here.
Questions about gear position sensors keep coming up here and more information would benefit everyone.