Hello,
You can update the plugin in Appearance > Install plugins. If you have any problems (these problems are often caused by the host security or size max size limitations) you can upload the recent version of the plugin on this forum in your profile and install via Dashboard > Plugins or FTP.
1. Make the full backup of your site.
2. Deactivate and delete the current version of the plugin.
3. Upload the new version from your portfolio on this forum.
4. Upload and install in Dashboard > Plugin.
Best Regards