The long-awaited Windows 10 Creators Update is now available to PC users despite the fact that Microsoft hasn't yet officially announced its availability.
ISO files for Windows 10 build 15063 (rumored to be the Release to Manufacturing (RTM) build) recently appeared on Microsoft's servers and there are two ways to go about the installation process.
Optionally, as Neowin outlines, you can pick up a new version of the Windows 10 Update Assistant and use it to update to build 15063. Be warned, however, that if you have the previous version of the Assistant tool on a PC running the Anniversary Update (or an earlier version of Windows 10), it'll tell you that your device is up-to-date and leave it at that.
Microsoft as of writing has not revealed when it plans to officially roll out the Creators Update to the general public (it hit the Windows Insider fast and slow rings last week). Although this appears to be the final RTM build, it's always possible that Microsoft could squeeze in a last-minute bug fix or two between now and the public launch which most expect will take place on April 11 (Patch Tuesday).