Well at last I managed to pull this one off.
A Bosch multipurpose Carbide drill bit was able to penetrate.
I started off with a 1/8" then something that would be OK for a 1/4 20 tap.
If you do this be very careful because you can easily break the tap. Also you need to go in a little and then grind the head of the tap off as there is very little clearance between the body of the compensator and the internals.
I used Redline Synthetic Moly grease. Again it needs only a small amount, do not be fooled by the size of the compensator. Apply very carefully in order not to breach the seal that I was informed by my dealer the compensator has.
Conclusion? A very hard road but well worth it because that early morning sound is gone.
