The tutorial I posted earlier is derived from an article posted by Windows...... Media Creation Tool.
BUT, the tutorial is precise and it shows you how to create the ISO and nothing else.
How to use the ISO for "in-place" upgrade :
After you have created the ISO, right click at it > click Mount > click Setup,exe.
Installation will begin.
This method allows you to keep you file, settings and apps, or you can choose to keep nothing.
This method does not require a product key.