tmaleshafske
The server manager Remote Management panel allows you to configure specific host IPs that can access server manager, user manager and user password pages.
The user manager contrib (which will allow password changing) can also be seperately configured with db entries to specify allowed host IP's.
It's not advisable to do, but you can open access to all external hosts, search the forums on Remote Management for the answer. Note that anyone can then access your server manager.