I'm guessing it's bonded in with epoxy - could you heat it up to get the epoxy to debond (which it already has!) and then hope it rebonds as it cools?
Thermosets don't work like that. Once they are cured that is it.
I don't know what the people who fix these would do but I would consider vacuum bagging the BB area and infusing it with some epoxy to try and get it to bond in.
Heating is not a problem, they are cured using heat and you can take it back up to near it's cure temp with no worries. But you need to know the cure temp so you don't overdo it and have a well controlled oven that is big enough.