Check this reference.
Removing a script element does not do anything. If you can somehow access a script element, it was executed a long time ago and removing it will have no effect.
Following will totally remove them from DOM only but not effect to code at all because already they are executed before. So be sure you don't need them at all to that page. Apply them before that script loads and after jquery load. like:
<script>
$('script[src="/Scripts/jquery.validate.js"],
script[src="/Scripts/jquery.validate.unobtrusive.js"]').remove();
</script>
<script src="/Scripts/jquery.validate.js"></script>
<script src="/Scripts/jquery.validate.unobtrusive.js"></script>
But I would prefer not to remove them, because they will harm other I believe.