Change the SkeletalMesh of a Character class

What is the proper way to load the mesh? The below doesn’t work.

static ConstructorHelpers::FObjectFinder New_Mesh(TEXT("SkeletalMesh'/Game/Mannequin/Character/Mesh/SK_Mannequin.SK_Mannequin'"));

I’ve seen references it’s bad to hardcode asset references, but I don’t understand how you could random or let the player select a new skin without this.