Place a copy of your Sitecore.Kernel.dll assembly in /lib/sitecore/v7 (for v7/v8)
Build the project for your Sitecore version using Visual Studio 2012 or later
Copy Unicorn.dll, Rainbow.dll, Rainbow.Storage.Sc.dll, Rainbow.Storage.Yaml.dll and Kamsar.WebConsole.dll to your main project in whatever fashion you wish (project reference, as binary references, etc)
Copy Standard Config Files*.config to the App_Config\Include\Unicorn folder
Configure to your liking; the setup README file is a good starting point.
Hit $yoursite/unicorn.aspx to perform initial serialization of your configured predicate