New syntax is:

plesk_password_changer.php <old admin password> [new admin password] [options]
Where [options] can be:
    –all – [default] reset passwords for all supported entities
    –admin – reset password for admin
    –resellers – reset passwords for resellers
    –clients – reset passwords for clients
    –domains – reset passwords for main FTP account of domains
    –domainadmins – reset passwords for Domain Administrators
    –users – change passwords for hosting panel users
    –additionalftpaccounts – reset passwords for additional FTP accounts for domains
    –subdomains – reset passwords for subdomains. NOTE: For Plesk 10.x subdomains treated as domains.
    –webusers – reset passwords for Web Users
    –mailaccounts – reset passwords for mail accounts

For example, next command

"%plesk_dir%additionalPleskPHP5php.exe" -d safe_mode=0 plesk_password_changer.php setup s3$ret! --admin --clients

means that passwords for admin and clients will be reset, password for admin will be "s3$ret!" (without quotes)