How to remove phpass ?

I too found this to be an issue on a live site I was using. While staying logged in, I uninstalled phpass then I just put the following script into a node/add form with the php filter turned on then clicked preview one time. Be sure not to save it in the node.

Warning, this script could take considerable amount of time to execute depending on the number of users you have:

function createPassword($length) {
  $chars = "23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNPQRSTUVWXYZ";
  $i = 0;
  $password = "";
  while ($i <= $length) {
    $password .= $chars{mt_rand(0,strlen($chars))};
    $i++;
  }
  return $password;
}
function resetPasses() {
  //$i = 0;
  $result  = db_query("SELECT uid, name, mail FROM {users} WHERE pass = 'phpass'");
  $from = 'admin@example.com';
  $subject = '[Site Name] Important Account Details';
  $headers  = 'MIME-Version: 1.0' . "\r\n";
  $headers .= 'Content-type: text/html; charset=UNICODE-1-1-UTF-8' . "\r\n";
  $headers .= "From: $from\r\n";
  $setmsg = 'Passwords have been regenerated and emails sent for the following users:';
  $message = "
    Dear %s,<br /><br />
    Due to needed upgrades, your Site Name site password has been reset.  Here are your new credentials:
    <blockquote>
      User: %s<br />
      Pass: %s
    </blockquote>
    Sorry for any inconvenience.  Once you login, you may change your password by navigating to \"My Account.\"<br />
    --<br />
    The Site Name Team";
  while ($user = db_fetch_object($result)) {
    //if ($i < 20) {
      $username = $user->name;
      $uid = $user->uid;
      $email = $user->mail;
      $password = createPassword(8);
      $msg = sprintf($message, $username, $username, $password);
      db_query("UPDATE {users} SET pass = MD5('%s') WHERE uid = %d", array($password, $uid));
      mail($email, $subject, $msg, $headers);
      $setmsg .= '<br />' . $username;
      $i++;
    //}
  }
  drupal_set_message($setmsg);
}
resetPasses();

be sure to change the Site Name and email and such to suit your needs. This could be added to the uninstall script if someone were so inclined.

Note, if you are getting timeouts trying to run this then it might be useful to comment in the commented out lines and just run a few emails at a time. It is currently set to do 20 if he lines are commented in.

glad your issue was solved. I originally installed for integration between phpBB3 and Drupal but have since converted the whole site to Drupal. I recently found another module that seemed to conflict with phpass so I needed to convert everyone to MD5.

The above script should do it, or you could use http://drupal.org/project/password_expire to force users to change their passwords.