Hi there,
Thanks for writing in! I’m not sure whether you want to update WordPress OR X theme & Plugins.
To update X theme & plugins, please refer to our guide here (https://community.theme.co/kb/updating-your-theme-and-plugins/). Also you can enable automatic updates by validating X theme. To do that, please refer (https://community.theme.co/kb/product-validation/).
If you want to update WordPress and other 3rd party plugins, Head over to your WordPress backend Dashboard -> Updaets section.
Hope that helps.