To change the default author slug/url, simply add the following to your functions.php file:
add_action('init', 'set_new_author_base'); function set_new_author_base() { global $wp_rewrite; $author_slug = 'new_slug'; $wp_rewrite->author_base = $author_slug; }
Once you have added this code to your functions.php file, you need to go to Settings > Permalinks then click “Save Settings”.