I'm currently preparing an adventure in which the players encounter an earth elemental in a mine and want it to leave the mine. I expect them to try to find a peaceful solution. From @Erik in another thread I got the idea that the characters could try to help the elemental get back to the Plane of Earth.
Regarding the question of how it got here, I will likely go with the "dropped through a randomly opening rift accidentally" version, as I don't want to create a whole new adventure finding the caller of the elemental or exploring a fully functioning portal.
Is there a way for level 1 players to help the elemental get back to the Plane of Earth? What could they do and how could an earth elemental return to the Plane of Earth at all?
(Considering the default Pathfinder setting, as I'm not ready to create a completely new world yet)