此脚本将执行以下操作：

function wpse_287807_replace_url() {

    // Get all posts
    $query = new WP_Query(array(
        \'post_type\' => \'post\',
        \'posts_per_page\' => -1,
    ));

    $posts = $query->get_posts();

    foreach ($posts as $post) {

        // Get permalink
        $url = $post->post_name;

        // Stop words array
        $stop_words = array(
            \'-a-\',
            \'-the-\',
            \'-of-\',
        );

        // Replacement
        $replacement = \'-\';

        // Replace url
        $new_url = str_replace($stop_words, $replacement, $url);

        // Prepare arguments
        $args = array(
            \'ID\' => $post->ID,
            \'post_name\' => $new_url,
        );

        // Update post
        wp_update_post( $args );
    }
}

add_action(\'init\', \'wpse_287807_replace_url\');

define( \'WP_POST_REVISIONS\', false );