It is a possibility that the broken part may come out if worked a little around the edges of the broken part stuck in the bell-housing.I have even had them come out with just my fingers(watch out for sharp edges).
The most likely situation will be having to find someone who has an angle-head drill that is reversable and a left handed drill-bit.You may have to take the bell-housing out of the truck to get to the culprit(broken piece).

(Or maybe get all believing stovebolters to pray that it will come out willingly!!)

There is enough good in the worst of us and enough bad in the best of us that it does not behoove any of us to criticize the rest of us.
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Be yourself. If you are ever lost, It will be much easier to find yourself if you know who you are!