How to update a 3rd Party Plugin
Always follow the instructions provided by the developer of a 3rd Party Plugin.
Remember to perform a FULL backup of your Joomla! CMS (database, directories and files) before you do.
If there are no update instructions from the developer, then as a general rule, you may try installing the latest release of the 3rd party plugin over the existing one.
If in doubt, ask the developer.
Always Perform a FULL Backup FIRST
Back up your website before updating 3rd party plugins.