Remove Font-Awesome MaxCDN Link & Load Locally

You must find the name of the enqueued stylesheet in your theme and use it to dequeue a style – wp_dequeue_style. URL is unnecessary.

Example:

function remove_unwanted_css() {
   wp_dequeue_style( 'font-awesome' );
}
add_action( 'wp_print_styles', 'remove_unwanted_css', 100 );

Or another solution wp_deregister_style/:

add_action( 'wp_enqueue_scripts', 'remove_default_stylesheet', 20 );
function remove_default_stylesheet() {
    wp_dequeue_style( 'font-awesome' );
    wp_deregister_style( 'font-awesome' );

    wp_register_style( 'new-font-awesome', get_stylesheet_directory_uri() . '/new.css', false, '1.0.0' ); 
    wp_enqueue_style( 'new-font-awesome' );
}