Removing System Preferences for an app

[Frank S. Fejes]

        Hello all.  In a couple applications I am currently making the
switch from System Preferences-based prefs to the app's own database.  When
a user upgrades to the new version of the app, I would like to be able to       remove 
all the older SysPrefs records so as to save some space.  How
can I do that?  I cannot seem to find any reference to removing those
types of records in the docs or the header files.  As always, thanks
in advance.

--frank