includes/templates/YOURTEMPLATE/templates/tpl_modules_main_product-image.php
remove the <script..../script>content, and the <noscript> tag, and the closing </noscript> tag, leaving the content between the noscript tags.
Then edit to remove the words that say to click for larger image.
Then remove the A HREF if you don't want it clickable.
Code:
<script language="javascript" type="text/javascript"><!--
document.write('<?php echo '<a href="javascript:popupWindow(\\\'' . zen_href_link(FILENAME_POPUP_IMAGE, 'pID=' . $_GET['products_id']) . '\\\')">' . zen_image($products_image_medium, addslashes($products_name), MEDIUM_IMAGE_WIDTH, MEDIUM_IMAGE_HEIGHT) . '<br /><span class="imgLink">' . TEXT_CLICK_TO_ENLARGE . '</span></a>'; ?>');
//--></script>
<noscript>
<?php
echo '<a href="' . zen_href_link(FILENAME_POPUP_IMAGE, 'pID=' . $_GET['products_id']) . '" target="_blank">' . zen_image($products_image_medium, $products_name, MEDIUM_IMAGE_WIDTH, MEDIUM_IMAGE_HEIGHT) . '<br /><span class="imgLink">' . TEXT_CLICK_TO_ENLARGE . '</span></a>';
?>
</noscript>
becomes
Code:
<?php
echo zen_image($products_image_medium, $products_name, MEDIUM_IMAGE_WIDTH, MEDIUM_IMAGE_HEIGHT);
?>
Do similarly for additional-images file.
You may have to do some styling adjustments after making this change if the image doesn't appear as desired.