First. This is a hack and the news item is still in its early stages, and really, don’t do this if you have no idea what you’re doing.

XDA forum member RustyGrom found out recently on how to install Windows 10 Technical Preview for phones which is non-approved Lumia devices.

Interesting that Windows 10 have these limitations at all!

If you want to try on your own risk, follow this link!

Source:
XDA Forum