/www/wp-content/plugins/kboard/skin/default/document.php  내용에서 아래와 같이 문구 추가했더니 원하는 결과를 얻었습니다~.

감사합니다! 

            <?php if($content->isAttached()):?>

            <div class="kboard-attach">

                <?php foreach($content->attach as $key=>$attach):?>

             첨부파일: <button type="button" class="kboard-button-action kboard-button-download" onclick="window.location.href='<?php echo $url->getDownloadURLWithAttach($content->uid, $key)?>'" title="<?php echo sprintf(__('Download %s', 'kboard'), $attach[1])?>"><?php echo $attach[1]?></button>

                <?php endforeach?>

            </div>

            <?php endif?>

https://www.cosmosfarm.com/threads/document/41882