First of all, you should install the add-on. You can find the installation instructions in the How to install add-on article. After add-on installation and activation, new skins will be added to shortcode settings, during insertion of post to the editor.
Take the following steps to use new styles:
Open the dashboard;
Create new post or page;
Press the Insert shortcode button;
Select one of the following shortcodes: Heading, Spoiler, Tabs, or Quote;
Find the Style option and select one of the new styles from the drop-down list.