Updating a theme
Updates follow the same flow as the initial install. Go to Settings → Design → Change theme → Upload theme, select the new .zip, and click Activate. Ghost replaces the theme files while leaving your content and all settings intact.
Before you update
Section titled “Before you update”Check the theme’s Changelog page for the release you are installing. Breaking changes, if any, are noted there along with any settings that have changed name or been removed.