Change author permalinks

author-permalinks.php

function change_author_permalinks() {

    global $wp_rewrite;

    $wp_rewrite->author_base = 'leadership-team';
    $wp_rewrite->author_structure = '/' . $wp_rewrite->author_base. '/%author%';

    $wp_rewrite->flush_rules();
}

add_action('init','change_author_permalinks');