When Prestashop use for your e-commerce site, you can choose between different worldviews. To install a new PrestaShop theme, you must download and extract the archive locally on your computer.
You can download one provided by SiteGround PrestaShop themes free:
You should then upload your entire file folder to the theme of Prestashop reside in.Once you done this folder “theme” directory, log in to your shopping cart management area, go to Preferences -> Theme. In this menu, select from the list of available themes in newly uploaded theme, press the “Save” button.
Congratulations! Your theme is not installed! You can browse to your front-end application and check its new look.