Lore help sought: how might my players change a deity’s domains?

The short setup: my players believe they’ve angered a major deity and want to atone for their actions. Since the deity in question is Desna, who wants to reclaim the Beasts domain from Lamashtu, one of the "obvious" options is to help her achieve that goal.

I’ve been looking for lore about how PCs (and mythic ones at that) might be able to even nudge the cosmic balance such that one deity might take a domain from another.

I know the ultimate answer is "whatever the GM says works works". I’m hoping that there’s some obscure bit of lore that I’ve overlooked that might point in a helpful direction.

So: what, if any, precedent/lore/… is there in Golarion for mortals to change – or aid in a change to – a deity’s domains when there’s no chance of a negotiated transfer?