Fastest way to get rid of Snake's "horn"?

[Scora]

I try to play nice and stealthy but sometimes i need to get my hands dirty. I dont feel i've been overly evil but still my shrapnel horn thingie keeps on growing :o

[Kezrian]

You can remove it: http://www.gosunoob.com/metal-gear-solid-5/demon-snake-guide-mgsv-the-phantom-pain/

[DestroyerJamie]

Which "horn"? <=3