That's a problem... I don't think I'd try to remove the broken piece on my own. It would definitely be worth having a professional do it, either in the care (if you can find it!) or by taking the head to a machine shop.

Is that the one that caused problems before? The one that the PO fixed for you?

Hard to tell, but did it break off right up against the head casting or is there some sticking out?

I have a Bus tow bar and can drag it somewhere if you need help. Be cautious about driving it like that