> Download or Clone Mono.Cecil source code from github.
> Open Solution file (Mono.Cecil.sln) with your Visual Studio.
> Build Solution (Compile). There are 12(Debug & Release) build configurations available. Choose the one that fits your needs.
.Net 2 Debug/Release
.Net 3.5 Debug/Release
.Net 4 Debug/Release
.Net 4.5 Debug/Release
Windows Phone Debug/Release
> Add Mono.Cecil.dll in your project, as a reference.