Make sure you also read the (unfortunately not yet complete) manual to get a better understanding. These pages are for reference and exploration only, and not intended as a tutorial or how-to.
To use Anewt in your own code, this line of code suffices:
require_once '/path/to/anewt/anewt.lib.php';
Now you can load modules like this:
anewt_include('database');
Good luck!
1.5.9