Download Windows Insider App to receive Pre-release OS updates
Microsoft has already announced Windows 10 Technical Preview for Phones Update for six Lumia devices including Lumia 630, 635, 636, 638, 730 and 830. Rest other Lumia phones will get included for this new update later in future. If you are using any one of these listed Lumia phones, then you will be first to test out the Windows 10 Technical Preview. But, this update will neither be available via OTA or via Zune PC Suite. You will need to have Windows Insider App.
Yes, that’s correct. You need to first install Windows Insider App on your Windows mobile, sign in to insider program and run download and install process. If the Windows 10 TP for Phones is available for your model number, you will see the download option. Download the same and test out all new Windows OS. So, what are you waiting for, go ahead and download Windows Insider App right away.