Don't do that to it. Upstream sensors affect your air/fuel ratio. I'd soak the bung down with some penetrating oil (kroil, pb blaster, etc. Not WD-40) for a day or two if you don't need to drive it. Start it and let it idle for a few minutes to get the manifold "warm", shut it down and slap a 6 point socket on it with a breaker bar. Get it broke loose and work it back and forth to clear the threads as you remove the remainder.Yeah hopefully not or I may just jbweld it back in there..maybe that would work.
Before installing the new one, clean the threads with a thread chaser if you can get one, and apply anti-sieze to new sensor. Use care not to contaminate the sensors 'nose' with anti-sieze.