Command/CreateFieldsOnGroupCommand.php
protected function deleteFieldsForCFGroup($customFieldsGroup)
    {
        $em = $this->getContainer()
            ->get('doctrine.orm.default_entity_manager');

        foreach ($customFieldsGroup->getCustomFields() as $field) {
            $em->remove($field);
        }
    }
protected function deleteFieldsForCFGroup($customFieldsGroup)
    {
        $em = $this->getContainer()
            ->get('doctrine.orm.default_entity_manager');

        foreach ($customFieldsGroup->getCustomFields() as $field) {
            $em->remove($field);
        }
    }
Delete the existing custom fields for a given customFieldGroup

@param CustomFieldsGroup $customFieldsGroup : The custom field group