It is reported that XDA Forum God has found a solution to upgrade all WP8 mobile phones to Win10 mobile phone preview. Its essence is to make Windows Insider APP "think" that all WP8 smart phones have Lumia635, which enables it to download and install Windows 10 mobile phone preview. However, this process requires the user to change the ID of the phone.

The preliminary report shows that if you successfully upgrade to Windows10, the "Phone Update" setting function is no longer available. If you want to restore this function, users need to set up 17 steps and know the correct country code.