Hi
You can use this css to hide it:
div#back-to-top {display: none;}
or if you want to remove code generating it, you go to footer block you're using:
/templates/ja_mixstore/tpls/blocks/footer.php
and remove this snippet of code:
<!-- BACK TOP TOP BUTTON -->
<div id="back-to-top" data-spy="affix" data-offset-top="200" class="back-to-top hidden-xs hidden-sm affix-top">
<button class="btn btn-primary" title="Back to Top"><span class="icon ion-ios-arrow-up"></span></button>
</div>
<script type="text/javascript">
(function($) {
// Back to top
$('#back-to-top').on('click', function(){
$("html, body").animate({scrollTop: 0}, 500);
return false;
});
})(jQuery);
</script>
<!-- BACK TO TOP BUTTON -->