Brooklyn provides options to change the default “portfolio-item” slug. In this case open your Dashboard > Settings > Portfolio Settings and use the field “Portfolio Slug” to add your own. Once you have saved the new slug, please open Settings > Permalinks and simply save everything. There is no need to change any of the options displaying on this admin page, just save and you are done! If further steps are required such as modifying the .htaccess file, WordPress will prompt a note about it.