if you have valid home licence, thendowngrade is possible with a little trick
open registry editor
follow this path:
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
change:
EditionID - Home
ProductName - Windows 10 Home
then go to this path:
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion
change:
EditionID - Home
ProductName - Windows 10 Home
then insert windows 10 installation media, run it fromm desktop and do in place upgrade while keeping files etc and enter home key once it asks for it