The ARC assets should be placed here:
Mac:
/yourUserAccount/Documents/Native Instruments/Kontakt 5/pictures/ARC/ *(this whole folder)
/yourUserAccount/Documents/Native Instruments/Kontakt 5/presets/MultiScripts/ARC 1.06.nkp
Windows Vista, Windows 7:
Documents\Native Instruments\Kontakt 5\pictures\ARC\ *(this whole folder)
Documents\Native Instruments\Kontakt 5\presets\MultiScripts\ARC 1.06.nkp
Windows XP
My Documents\Native Instruments\Kontakt 5\pictures\ARC\ *(this whole folder)
My Documents\Native Instruments\Kontakt 5\presets\MultiScripts\ARC 1.06.nkp