1) Add the field "PWD_Synced" in the phpBB3 table phpbb_users. You can use the following statement.
	"ALTER TABLE `phpbb_users` ADD `PWD_Synced` BOOL NOT NULL DEFAULT '0';"
2) copy phpBB3Auth directory to your vb forum installation directory
3) change the path to controller.php directory in phpBB3-plugin.xml
4) copy the hooks_phpBB3.xml to FORUM_ROOT/inclucdes/xml directory
5) in login.php do:
    search for: 
      if ($vbulletin->GPC['vb_login_username'] == '')
         {
          eval(standard_error(fetch_error('badlogin', $vbulletin->options['bburl'], ....
         }

   insert below:
      ($hook = vBulletinHook::fetch_hook('phpBB3_login_hook')) ? eval($hook) : false;

6) activate plugin system (if not done already) in admincp
7) in admin cp import the product file "phpBB3-plugin.xml" at "Download / Upload" Plugins
8) re-check if the include for controller.php is right
9) in includes/class_bootstrap.php search for: 
      $show['nopasswordempty']
    change: defined('DISABLE_PASSWORD_CLEARING') ? 1 : 0;
    to:     defined('DISABLE_PASSWORD_CLEARING') ? 0 : 1;
10) test the product
