Adding library to MS Visual Studio for Modbus

Hi, I have a Netduino N3 ethernet that I want to use for a project with modbus TCP. I downloaded files from github (not sure if I can post links yet). Modbus library from highfield/cetdevelop https://github.com/highfield/cetdevelop. I am new to using MS Visual Studio so not sure if I have the terminology correct and I don’t know how to add the library so I can use it in my project.

Thank You!