You can achieve that by following my below suggestion
+ Open templates/ja_mero/ja_mero/tpls/blocks/header.php file
From
<!-- LOGO -->
<div class="span8">
<div class="logo logo-<?php echo $logotype ?>">
<h1>
<a href="<?php echo JURI::base(true) ?>" title="<?php echo strip_tags($sitename) ?>"<?php echo $logoimage ?>>
<span><?php echo $sitename ?></span>
</a>
<small class="site-slogan hidden-phone"><?php echo $slogan ?></small>
</h1>
</div>
</div>
<!-- //LOGO -->
Change to
<!-- LOGO -->
<div class="span12">
<div class="logo logo-<?php echo $logotype ?>">
<h1>
<a href="<?php echo JURI::base(true) ?>" title="<?php echo strip_tags($sitename) ?>"<?php echo $logoimage ?>>
<span><?php echo $sitename ?></span>
</a>
<small class="site-slogan hidden-phone"><?php echo $slogan ?></small>
</h1>
</div>
</div>
<!-- //LOGO -->
+ Open templates/ja_mero/css/custom.css file
Add new script
.logo {
float: left;
}