Change position of specific instanced static mesh

I’m trying to make a blueprint that will place stalactites along a spline and when the player shoots one of them, the one that was hit will fall.

I don’t know how to select the specific instance, based off of the hit by the player, to make it break off of the cave ceiling.

My construction script:

Random instance Function:

I have no idea where to start with this. I’ve had a look at the documentation, but there isn’t much help for what I want to do.

I believe for hierarchical instanced static meshes you are looking for this setup.