How to downgrade from Windows 10 to Windows Phone

[Mobitelijas11111]

I forgot to make a backup partition for my Lumia 640XL Dual SIM. WPinternals says the phone is still booting, but how do i bring it back

[RedGreenBlue09]

Can you give more infos? What can you do with your phone right now?

[Mobitelijas11111]

I can only boot to Windows 10. And if i press the volume down button, i get the production signed developer menu from https://github.com/Empyreal96/W10M-16212-Guides/wiki/Update-using-Universal-Updater

[RedGreenBlue09]

1. Connect your phone to the PC
2. Open WPinternals
3. Click "interrupt boot process"
4. Reboot phone
5. After rebooting, the phone should be in flash mode
6. Flash ffu

[Mobitelijas11111]

Thank you! This helped and can you put this in your guide, in case the phone is ONLY running windows 10, and the windows phone partition got formatted