Go in your backend to components->compojoomcomment->setttings ->com_content -> layout.
There play with the options -> say that you want to modify the tempate that you use, save and you'll see 2 new tabs - one html and one css - > go to the html tab and find this code:
{readon}
<div class='write_comment'>
<a href="{READON_LINK}#JOSC_TOP" class="readon">{READON_WRITE_COMMENT} ({READON_COUNT} {READON_COMMENTS})</a>
</div>
{BLOCK-preview}
<div class='comment_preview_container' style='clear:both'>
{preview-lines}
</div>
{/BLOCK-preview}
{/readon}
change it to:
{readon}
<div style="clear:both"></div>
<div class='write_comment'>
<a href="{READON_LINK}#JOSC_TOP" class="readon">{READON_WRITE_COMMENT} ({READON_COUNT} {READON_COMMENTS})</a>
</div>
{BLOCK-preview}
<div class='comment_preview_container' style='clear:both'>
{preview-lines}
</div>
{/BLOCK-preview}
{/readon}
this should do the trick.
Daniel