Loose skin

Hi all.

This is weird, but im going to try my best to explain. My friend has lost ALOT of weight, like 13kgs and he is @ 9.5+-% bodyfat. The thing is his only got some fat on his lower abs and upper legs, but his arms has alot of loose skin it seems, it doesnt feel like theres any fat like on his belly, just feels like a big piece of stretchy skin. How do you get rid of this?

Stretched skin takes a while to tighten up again, months even. If it's very stretched the best way is to fill is with big vascular muscles.

Thanks bro, hahaha shame so theres nothing that can aid in the skin diminishing? He HAS to fill it?