Blazor is now shipping as part of .NET Core 3. Installing Blazor is now as simple as installing version 16.3 or later of Visual Studio! You can download the latest Visual Studio preview by following this link.
DotNet Cli commands and client-side Blazor (WebAssembly) can be installed by executing the following command in an command line window.
dotnet new -i Microsoft.AspNetCore.Blazor.Templates::3.1.0-preview4.19579.2