Windows 8 Upgrade Help !

Hi !

I  brought a new Dell Inspiron 15R SE 7520. I'm very satisfied with this Laptop.But,it has Windows 7 Home Premium x64 Bit Pre-Installed and I want to upgrade it to Genuine Windows 8 x64 Bit (DELL OEM).

So,How can I upgrade it to Windows 8 x64 Bit ?

Does the "Windows 8 Upgrade Offer" is eligible for me?

Also,Does DELL provide Windows 8 OEM Disc(s) ?

Thanks in Advance !