Put this kit in its own kit directory within your styles source directory, preferably as a submodule of your project to allow easy updating.
git submodule add git://github.com/DavidOliver/styles-compass-kit.git kit
Copy the files in the starting-point directory to your styles source directory. These copies are the files to edit. Files within the kit directory should not be edited so as not to cause complications when updating the kit.
In _base.sass, configure the configurable variables as required, uncommenting lines as necessary.