You don't have to change Windows 10 to Windows 7, it's a downgrade. Anyways you need a bootable device with Windows 7 OS

It's easy u Can watch videos on YouTube kalfelek Windows 10 file 5.69 Gb awrdeh bekelalu install mareg tchlaleh alebelezia computer balemoya gar mewsed tchlaleh eske 500 brr yaskefluhal