Windows Phone 8.1 to Windows Mobile 10

[Windows Central Question]

Hello, i had windows mobile 10 installed on my Lumia 1020.Because of a problem i had to install windows phone 8.1 on my phone and now i want to update again to windows mobile 10, but since it's not available for Lumia 1020 i can't. Is there any way i can update my phone to Windows Mobile 10?

 

[xandros9]

The Insider program awaits. Use the Release Preview ring.

 

[Rinsun]

It seems Insider programme is no longer available for those phones which did not get the public release.My son was on 8.1(Denim) on Lumia 630 DS.(India).Since he was not eligible for the public release he tried through Insider app.After signing in with his MS account it says 'No new build available'.Rings did not show up either:unhappy:
Link-
Supported phones for Windows Insider Preview - Microsoft Windows

Is there any solution ? Thanks.