Are you saying that the threads are out and just the shaft is spinning? That should be an easy one for a home made puller, as the top of the center electrode is threaded. My no. 6 snapped just above the threads, the two halves held together by the center electrode. The hex portion was just spinning, but the threads still in the head did not move. Hope that is not your case. Mine required a laborious drill out, after oil filter housing removal. On the plus side, I did get more intimate knowledge of the 606.