Downgrade from Windows Phone 8.1 (installed; not an update) to Windows Phone 8

Question

I'm considering buying a Nokia Lumia 730 (or 830), but it comes with 8.1 preinstalled, while I'd like to be using WP8 instead.

Is there any way I could downgrade?

All the solutions I could find on the Internet apply to the devices updated OTA.

I can also see the similar questions:

• How to rollback Windows Phone 8.1 update? - the difference is that the device was upgraded OTA in this case, while the one I'm about to get comes with WP8.1
• How to install Windows Phone 7 on a Windows Phone 8 device? - there are hadware differences in this case that shouldn't apply to the 8.1 <--> 8 transition

Answer 1

No, it's not possible for the Lumia 735 (or 730) or 830.

Those devices shipped with the Windows Phone 8.1 OS which means that's the minimum version the devices will run.

There is no version of 8.0 for those phones, which would have to include low-level driver support for on-screen navigation keys, newer CPUs, camera modules, etc.

Answer 2

Your question can be answered, but you can (only) do that if you have a professional knowledge about hardware and software of Windows Phone. One of my friends did it and it worked, but I recommend you do not try to do that, may be risk !