The uk.ac.ox.usrgrpgen package is used to create new users and groups for the Bodington system.
The class uk.ac.ox.usrgrpgen.OfflineGenerator can be used to run it from the command line, just make sure the Bodington system has been shut down in advance.
To run it from within Bodington use the uk.ac.ox.usrgrpgen.ImportManager class.