1. Идем на Редактор страниц > Управление дизайном > Мини-чат - Вид материалов.
2. Заменяем все на:
Code
<div class="cName"><span style="color: green; margin-right: 6px; font-size: 10px; text-align: left;">$TIME$</span>
<a class="subforum" href="$PROFILE_URL$"">$USERNAME$</a>:
$MESSAGE$
</div>
<div class="cMessage" style="border-bottom: 1px dotted #dddddd; padding-bottom: 5px;"></div>

3. Идем на Форму добавления сообщений и заменяем все на:
Code
<style type="text/css">
.postSubmit {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #6eb300;
color: #ffffff;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}
.postSubmit:hover {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #83ca12;
color: #f3f3f3;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}
.postReset {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #d82020;
color: #ffffff;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}
.postReset:hover {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #e33939;
color: #f3f3f3;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}
.postPreview {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #666666;
color: #ffffff;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}
.postPreview:hover {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #888888;
color: #f3f3f3;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}
.postReset {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #d82020;
color: #ffffff;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}
.postReset:hover {
border: 0px;
padding: 5px;
text-align: center;
font-size: 10px;
margin: 0px;
width: auto;
background: #e33939;
color: #f3f3f3;
cursor: pointer;
letter-spacing: 0px;
font-family: verdana;
}

</style>

<input type="button" href="$ACTION_URL$" onclick="window.location.reload();return false;" title="Обновить" style="height: 24px;;width:30px;margin:0px" value="©" class="postReset">

<input type="button" class="postPreview" onclick="window.open('/mchat/0-1','mchatCtrl','scrollbars=1,width=550,height=550,left=0,top=0'); return false;" style="height: 24px;width:30px;margin:0px" value="mail">

<input type="text" maxlength="60" name="uname" size="8" class="mchat" id="mchatNmF" value="" onfocus="ffoc(this,0)" onblur="fblur(this,0)" title="$STR_NAME$" style="display: none;height: 24px; color: #777777; font-family: Verdana; border: 1px solid #aaaaaa; background-color: #f1f1f1; background: url('http://coool.net.ru/images/1/main_top_gradient.png'); background-repeat: repeat-x; background-position: left top;">

<input type="text" maxlength="$MAX_MESSAGE_LEN$" name="message" size="22" class="mchat" id="mchatMsgF" value="" onfocus="ffoc(this,2)" onblur="fblur(this,2)" title="Сообщение" style="width: 68%; font-size: 7pt; padding: 5px; margin: 0px; font-family: Tahoma; height: 24px; color: white; font-family: Verdana; border: 1px solid #aaaaaa; background-color: #f1f1f1; background: url('http://coool.net.ru/images/1/main_top_gradient.png'); background-repeat: repeat-x; background-position: left top;">

<input type="submit" style="height: 24px;width:30px;margin:0px" value="»" class="postSubmit" id="mchatBtn" onclick="return checkform(this.form);">