All you need is a 22mm open-end wrench and some PB blaster. I would spray the part where the sensor screws into the manifold and let it soak for a day. Then I would get at it with the wrench. Thats exactly what I did with mine. Sometimes the sensor will freeze upon removal when you're unscrewing it. If that happenes you're going to need to get a new sensor and probebly re-tap the manifold bung.