Rear wheel abs sensor stuck

[ManofKent]

Hi.
The right hand rear wheel sensor for abs and esp is faulty and needs to be changed.
My problem is how to get the darned sensor out. It is stuck like it was welded in!
After many hours of trying I have drilled into it (carefully) and threaded it M4. It now has a long M4 bolt in it which I have prized, wiggled, made a special two pronged tool to get it out.
It still will not budge.
Has anyone else had this issue? , and if so how did you do it.

All suggestions gratefully received.

Many thanks

John

 

[AltonAnt]

In the past I have knocked them out with a punch from the outside. I does involve a bit more dismantling unfortunately.