Is there a way to reset Moodle back to the default roles? From what I've read in the Moodle docs there isn't but we've got a site that we're trying to upgrade from Moodle 1.9 to 2.0 and, unfortunately, certain users were given Admin rights on the 1.9 version and there are a number of issues with the roles they'd set-up (without truly knowing what they were doing). Some of it is as simple as renaming archetype roles whereas, in other instances, they either created new roles with no archetype basis or deleted role rights and permissions without any documentation on why they did what they did.
Starting from scratch and migrating content and users to a brand-spanking new site is not an option...