given that this piece is hollow, not sure if this will work but I have used to with success in the past.
Get a solid M12 bolt that is far too long. Get some Super Glue Gel (or if you can find them the little Superglue Dots). Apply the glue to the end (not threads but the flat tip) of the bolt. Quickly screw it in until it contacts the remaining piece. Let it set for 2 minutes. Then gently unscrew the bolt with HOPEFULLY the piece glued to the end.
This will either A: remove the piece or B: go ahead and drive it into the pan. Sounds like you are in for a Oil pan drop regardless.
Buddy of mine had this sort of happen to him at a Quick Lube place. They sheared off the pan plug bolt about half way in.(Was likely misthreaded) Of course, they just unscrewed the remaining, cranked in a new bolt as far as it would go, and then hammered the bolt head until it was flush with the pan.
Yep, lawyers were involved. Yep, he got a new engine out of it. Yep, I did however initially have to stop him from killing the mgr. at the Quick Lube.