Themes
From: Using Back-End
Themes can change your website look.
Install, Update, Downgrade and Repair
Read Install section for installing theme.
Set Theme as Default
Core using default theme for the front-end. To set a theme as default, go to the Themes/Theme Manager. Click on Set as Default button.
Settings
Each theme can have main settings. Go to the Themes/Theme Manager. Click on Settings button. If the theme has settings, you should see the settings tab.