Write your forwards methods here.

def forwards(self, orm):
        "Write your forwards methods here."
        # Note: Remember to use orm['appname.ModelName'] rather than "from appname.models..."
        for c in orm["contenttypes.contenttype"].objects.all():
            if c.app_label == "DublinCore":
                c.app_label = "dublincore"
                c.save()