How to upgrade win10 9901 to win10 9916?

In 2015, the update plan for the Microsoft Windows 10 Technology Preview will be re-launched, and two of them are very close to us.
When the foreign media leaked Windows 10 Bulid 9901 before use, it was found that two new versions have appeared in the Windows update settings, among which "slow ring" users can find Build 9916 update, and "fast ring" users You can find the Build 9918 update.
Unfortunately, although these two updates can be downloaded, they cannot be installed. Because Microsoft had confirmed that the leaked Build 9901 version had bugs, so it could not be upgraded to the latest version. This means that Build 9901 users can only upgrade by reinstalling them.
Foreign media said that this update will be improved in terms of functionality and user interface, but there is no clear news.