Within Your Windows 10 System Go To Start menu,
Click the “Update & security” icon and select “Recovery.”
You should see a “Go back to Windows 7” or “Go back to Windows 8.1” option
Click the Get started button to get rid of your Windows 10 install and restore your previous Windows install.
Select which os you want to roll back to
Type a reason why you want to roll back.
Reboot the system and its all automated. Thats it