[Plugin: Post Ratings] How to replace jquery link

My themes has been have a juqery link.
https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js

When I use Post Rating Plugin, My header will have a link /wp-includes/js/jquery/jquery.js?ver=1.7.1

So I have two jquery file in theme.

The plugins file (post-ratings/post-ratings.php) include

add_action(‘wp_enqueue_scripts’, array($this, ‘assets’));

when I remove this row, the plugins can’t work.

http://ww.wp.xz.cn/extend/plugins/post-ratings/