Announced today at the Microsoft Surface event in New York City, the Windows 10 October 2018 Update (build number 17663.1) is officially final, and it's now ready for you on Windows Update, Update Assistant and Media Creation tool (at the link below) : Windows 10 October Update v1809.
Not sure how you do this? Check the official information on Microsoft's blog post.
If you're a Windows Insider already on build 17663 you're good to go, although if you want to back away from the Insider program for a bit you may want to do a clean install and make sure all the Windows Insider cruft is gone. If you've been running the April 2018 update or previous and want to move up to the latest and the greatest, you can get to downloading now.