Scroll down to find Download Windows 8 UX Pack 7.0.
Click on the link provided.
Wait until the download is over and you get this file in a zip folder. Extract the folder to your desktop and open it.
Note that to extract a folder, you're going to need a program such as Winrar, 7-zip, etc.
Open it and you get a Windows box.
Click Configure. Leave your computer alone for five minutes until it wants to restart. Once you open your computer, your login screen will be somewhat like Windows 8. You'll get Windows 8 on your computer.
Tutorial By All in 1
If you don't get the Windows 8 on your computer, follow this path: My computer> Local Disk C> Program Files> UX Packs> Newgen> Activate Newgen.
Don't go to download anything other than this or you your computer may get unwanted viruses.