Update Free Theme
If you're using the free version of one of our themes, and if it is available publicly on the wordpress.org repository, then all you need to do is hit "Update" for the theme whenever the WordPress admin area displays a notification that an update is available.
Please note that if you have made any modifications directly to your theme files, then those edits/changes will be lost if you update the theme to the latest version. The best way to make changes in your theme is through a Child Theme.