How I Removed the Stuck O2 Sensor from my 2005 Toyota Matrix XRS

When I tried to remove the O2 sensor on my Matrix XRS, it was stuck, the O2 sensor socket wouldn't fit and the corners were already rounded. This is how I got it out.
Obviously this is a last resort before having to have the O2 sensor bung cut off the exhaust pipe and a new one welded on.
Remember to wear safety glasses etc when breaking off the sensor with a hammer and when using the impact wrench.
It should also be useful for Pontiac Vibe GT and Corolla XRS as well