Final answer:
To change the theme variant to the second variant, you would go to the theme settings and select the 'Second' variant option which offers customization such as different color schemes and font styles.
Step-by-step explanation:
To change the variant for the theme to use the second theme variant, you would typically go into the settings or options of the software or service you're using where themes are managed. From there, you would select the theme you're currently using and then choose the 'Second' option for its variant. Theme variants often represent different color schemes, font styles, or layouts that are alternatives to the main theme, providing a way to customize the look and feel according to your preference or needs.