How do I change a default Dashicon in WordPress Admin area?

Question

So I am renaming my "Posts" in WordPress backend to "News" and was able to use the code (thanks to Chris Perryman) added to my functions.php file but I would also like to change the default dashicon as well to: dashicons-media-document instead of the default "dashicons-admin-post"

I have tried adding: $labels->icon_url = 'dashicons-media-document'; but that doesn't work for some reason or other?

Thank-you in advance for any help!

function revcon_change_post_label() {
    global $menu;
    global $submenu;
    $menu[5][0] = 'News';
    $submenu['edit.php'][5][0] = 'News';
    $submenu['edit.php'][10][0] = 'Add News';
    $submenu['edit.php'][16][0] = 'News Tags';
}
function revcon_change_post_object() {
    global $wp_post_types;
    $labels = &$wp_post_types['post']->labels;
    $labels->name = 'News';
    $labels->singular_name = 'News';
    $labels->add_new = 'Add News';
    $labels->add_new_item = 'Add News';
    $labels->edit_item = 'Edit News';
    $labels->new_item = 'News';
    $labels->view_item = 'View News';
    $labels->search_items = 'Search News';
    $labels->not_found = 'No News found';
    $labels->not_found_in_trash = 'No News found in Trash';
    $labels->all_items = 'All News';
    $labels->menu_name = 'News';
    $labels->name_admin_bar = 'News';
}
 
add_action( 'admin_menu', 'revcon_change_post_label' );
add_action( 'init', 'revcon_change_post_object' );

I would like to be able to just add a simple line or two of code to my custom-themes' function.php so this will all get updated on a new install.

Answer 1

Use CSS

function bks_replace_admin_menu_icons_css() {
    ?>
    <style>
        .dashicons-admin-post:before {
            font-family: "dashicons";
            content: "\f497" !important;
        }
    </style>
    <?php
}

add_action( 'admin_head', 'bks_replace_admin_menu_icons_css' );

Code goes inside functions.php file.