No need for additional software or package, just click install and it's applied! Looks minty cool :)
Its ok! looks good background and icons works without any problem. I apply it within Grub-Customizer (to make it easier) dont know if it works just installing without touching grub stuff. The only "ugly" thing in my machine is that when you are in the grub boot menu and you press E for edit the "box" or lines arround the screen wont show lines, insted it shows some ugly characters... might need to add a font or something else.