Download the new product.cab zip archive from the Deskmodder website.Note that you don't want to execute the tool right away as it only offers version 1803 and not 1809, the version that you are after. Download the Media Creation Tool for Windows 10 version 1803 from Microsoft.You need to download two files to a PC and place them in the same folder. Windows 10 and Server 2016 update changes.Windows 10 version 1809: removed and deprecated features.The features and changes of Windows 10's October 2018 Update.Users who prefer an ISO can download it from Adguard instead or download the Media Creation Tool from Microsoft. You can select Settings > Update & Security > Check for updates to download and install it if Microsoft deems the PC compatible with the update. Update: Microsoft released Windows 10 version 1809 officially. The process itself is pretty straightforward note that it requires running a command from an elevated command prompt but that is all there is to it. The method described uses Microsoft's own Media Creation Tool to download the update and either install it on the machine it is executed on or create installation media on USB Flash Drives or as ISO images.
German tech site Deskmodder found a way to download the Windows 10 version 1809 update right now.