How can I edit the css for Busines Feature Theme

I installed the Business Feature theme and went to edit the css (I wanted to change the mossy green color of the feature areas). It simply alludes to using the buddypress css (see below). Where can I find the actual css file?

Also - is there a PDF manual for this theme?

Uses BP-Default theme files and styling for BuddyPress components with some customisation for theme.
Included in theme to allow for own child themes rather than being child of BP-Default

The CSS, XHTML and design is released under GPL:
http://www.opensource.org/licenses/gpl-license.php)