removed the three icons (search, guy, and shopping cart) but can’t

Hi

You can put the following custom codes into functions.php file (using child theme is a good way to customize the theme).

remove_action( 'lithestore_header', 'lithestore_primary_navigation',20);
add_action( 'lithestore_header', 'custom_primary_navigation',20);
function custom_primary_navigation(){
	 echo'<nav id="site-navigation" class="main-navigation ls-grid ls-col8" role="navigation">
	      <button class="menu-toggle" aria-controls="primary-menu" aria-expanded="false"><i class="fa fa-bars"></i></button>'.wp_nav_menu( array( 'theme_location' => 'primary', 'menu_id' => 'primary-menu','echo' => false ) ).'</nav><!-- #site-navigation -->';
}