I broke an extractor off in mine. The one you'll use is a very small diameter. Use a lot of PB Blaster first, over a day or two. I went through 2 or 3 bits, trying to drill out the broken extractor, but never did. It's my opinion that the 4 or 5 days of repeated soakings with PB and the vibration from the drill finally got it loose. I cut a slot across the head with a dremel just big enough to put a flat blade screw driver into, and it came out like it was never siezed. Just be carefull with the extractor.
And... Good Luck