Just to double check... you've removed the glow plug and the threaded ring?
It took me a while to pull mine... I had to beat on them with the slide hammer for a good couple minutes. Once it broke loose it still needed beat on to pull the rest of it out... so how much abuse have you given it with the slide hammer? Maybe it just needs a little more
Before you try to get the prechamber out though, you should check your injectors' spray pattern. It is simply amazing just how horrible the engine can sound from simply a bad injector!!!
Whenever you do get it put back together make sure you rotate the engine a couple times by hand to make sure that you didn't drop anything in there... trust me on this
Best of luck!
