Un mic script php. Poate va ajuta.

Cod:
<?php
$con = mysql_connect("localhost","user_db","parola_user_db");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("nume_db", $con);

mysql_query("UPDATE wp_users SET user_pass=md5('noua_parola')
WHERE user_login='nume_user_wp'");

mysql_close($con);
?>