You will need to compile the libraries for your system. This is mostly a C task, and if you have no experience compiling C libraries, this will be some learning experience for you. As the build scripts seem to be built using autoconf, there is little hope of getting the automatism to work on Windows, so you will have to do the configuration and compilation yourself, manually.
After you've successfully configured and compiled the library, you then have to point the Makefile.PL in File::LibMagic to the headers of the library and that should be it.
Personally, I would look at other libraries that determine the magic type of files, for example File::MimeInfo::Magic or File::MMagic.