You have to upgrade first to ensure that you get the license correctly. After that you can go into Settings and choose to reset or do a clean install.

You can find more information here.

You have to upgrade first to ensure that you get the license correctly. After that you can go into Settings and choose to reset, or do a clean install later yourself.

Microsoft has released a tool that allows you to upgrade or create installation media.

You can find more information on the upgrading and installation process here.