How to make a cloak for my character/Problems with colliders

I'm using Unity's asset Third Person Controller on my character, which needs Character Controller (a collider), I made a cloak, using clothes, but I can't put in on his shoulders because of his collider, how could I fix that?

I tryed to put an invisible collider into his shoulders but it falls down when I run the game, maybe I could filter collisions but I have no idea how to do that ._.