The easiest way to Disable Windows Defender is to simply run dControl on your device.
Download dControl Tool above, the password is Sordum
Upzip/Extract the file onto your Desktop or your own Folder (right-click Defender Control.zip, Extract)
Open dControl.exe (Nothing else)
Click the "Disable Windows Defender" Button until the tool turns red.
And you're done! Proceed to the next setup requirement.