Show Notification when hover on bell icon

Hi Plugin developer, really love your plugin and I have a 2 questions

1. I want to open the notification bar when hovering over bell icons currently it’s open when you click the bell icon(currently i achieved this by added some changes to shortcode.php file ) is there any easy way to do this?

2. How can I override the plugin file if I do any changes in plugin files so I will not lose my changes if I update the plugin to a new version when a new update released