Once you download the Operating system (.ISO file) you require to burn to a DVD using a burning software like Nero or a free CD/DVD burner .while installing Windows 8 you need to fresh install i.e its required to remove old operating system like Windows 7, vista, xp.The system requirements for Windows 8 is similar to Windows 7 and works great on the same hardware that powers Windows Vista.
Windows 8 Download Link: msdn.microsoft.com/en-us/windows/apps/br229516
