If after importing a demo in our WordPress theme you change your mind and want to import a different demo, you must completely clean the previous demo before importing the new one. This cleaning process can be done through the theme panel, and the path is shown in the screenshot below. Please note that all site content will be deleted during this process Dashboard > XTRA > Uninstall

If you want to reset all your WordPress data including posts, pages, settings, menus, and etc. You can also use a reset plugin, such as WP Reset, for this purpose.