Have you tried pressing it back together yet? That's all there is to it, unless something is damaged.
The pin goes into the hole and should have enough resistance to not turn by itself, and the magnet holds it together.
Sorry, I can't say how hard it should be to pull apart. Mine separated in a crash so I've not pulled it apart by hand.
Are you sure that it was pressed fully into position?
Maybe some others will chime in and assist with this.