Cannot include the installed Multilingual Toolkit in VS 2010 environment.
You probably need a new update because the latest version is compatible with the following: "Required software: Visual Studio 2013, including Express editions, Visual Studio 2015, including Express editions".
As you can see VS 2013 is supported. Follow the link below to reach the page from where you can acquire the Multilingual Toolkit.
Note: Click on the language you need to initiate the download.