Applying Layered Clothing

In “Beyond the dark” you can take the starter character and see his layered clothing already applied to his character. I am lost. I have spent so much time looking up tutorials and documentation but I just can’t figure this out.

Only solution I can think of is applying clothing by script but even that isn’t documented well…

I vaguely remember something about maybe fitting layered clothing to a character back when 7the announcement came out a while ago but I cant find it and the accessory toll wont let me apply to mine.