The most easy way to get Fluent Migrator and keeping up-to-date is from the nuget packages.
NuGet is a Visual Studio extension that makes it easy to install and update open source libraries and tools in Visual Studio.
You can install it from here
Once Nuget is installed, create a new Visual Studio library project for your migrations. Then launch the package manager console from Visual Studio:
In the package manager console, type:
PM> Install-Package FluentMigrator
Also if you would want to run migrations from the command prompt, nant or msbuild you need the Tools package:
PM> Install-Package FluentMigrator.Tools
Now you are ready to create your first Migration