– New version compatible with WordPress 5.0. May be need install Classic Editor plugin.
– The fast way is upload overwrite main theme files via FTP account to your server (wp-content/themes/<main-theme-folder>). You also can update theme via Envato Tool Kit plugin with setting purchased code.
– Update Lionthemes Helper, Visual Composer, Revolution Slider if they needed in theme version. You can deactivate, delete and install again from dashboard require, recommended plugins message.