It's mentioned in the tutorial, but here's a direct link to a utility from the Microsoft Store: Microsoft Store Online
I believe that you can run the tool and create an X64 installer from an X86 (32 bit) system.
The bad news is that the USB drive is formatted as NTFS. I don't know if whether it's a universal requirement, but in order to do a UEFI installation with my Asus motherboard, the USB drive has to be formatted as FAT. (There's no real need to do a UEFI installation with my motherboard, so that's not tragic.)
What do you mean "my motherboard has no DVD ports"? I'm unaware of any "DVD ports" on any motherboard. DVD drives are usually SATA, or IDE on older systems. You can buy a new SATA DVD burner for less than $20, including shipping. (I suggest Newegg, if you're in the US or Canada.)