The structure for neoWidgets is very simple. It consists only of header files, like the Standard Template Library. There is a include directory, which has a subdirectory neo.
Common installation choices would be to copy the framework to a central location, say "C:\neoWidgets_1_0", and let your compiler know about this directory. Alternatively you could copy the "include\neo" directory into the source of your own project.
Once the files are in a place where the compiler can find them, include them like this:
neo.h is the main header for the library. It includes all other necessary files.