heres a picture of the rog 120
https://www.google.com/search?q=asus+rog+g20+inside&espv=2&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjo2_X5krPTAhUk0YMKHUEeCRAQ_AUIBigB&biw=1745&bih=885#imgrc=7hzkZXEMgfX7gM:
you would first have to find a full tower case that will fit that board.... best way to do that is look at the rog 120 MOBO size is (which im sure is a micro or a mini) once you find a case for it its simple as putting it back together from what i can see