Fred is a collection of common CSS patterns for websites.
To build a custom Fred package from the command line, run:
> npm install
> grunt
...and follow the directions of your cabin crew.
Grunt will make a dist/lib/fred.scss, and compile dist/fred.css for your project
You want to tweak all Fred's variables and make everything pretty for your project.
You also want to keep Fred under some kind of package management, like bower.
The _fred-theme.scss is copied into your sass directory and included by lib/fred.scss.
// style.scss
@import "path/to/fred";
// Rest of your styles here!
Now you can tweak away, while still being able to update Fred without nuking all your hard work.