Disclosure: These steps (at least for me) worked until it was time to actually install the files, in the Windows installer. This may be a configuration or hardware issue, but I am not totally sure.
This will help you set up a boot drive to install Windows 10, using a Mac. If you have a PC, this should be easier, using instructions at: https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/install-windows-from-a-usb-flash-drive
- You will use a US version of Windows 10 (if not, then you may need to change the variables a bit)
- You have a detachable USB device (minimum 5GB)