You'd have to edit the theme template files to move the comments link. Open index.php, find this line and move it to the bottom.
<?php comments_popup_link('No comments yet', '1 comment', '% comments', 'comments-link', 'Comments are off for this post'); ?>
ideal place to paste it would be in the line above </div><!--.entry-->, just before the </p> tag.
Target it through CSS and change the color and size like this.
body.custom .comments-link {
color: #c00;
font-size: 14px;
}
Image:
Upload your image to the images folder and add a couple of declarations to the above CSS selector (final CSS below). You might have to play around a bit until you get the image right.
body.custom .comments-link {
color: #b00;
font-size: 14px;
background: url(images/pp-bullet.gif) 0 50% no-repeat;
padding-left: 15px;
}
change the 15px left padding depending on the size of the image.