The Password Reset Help:Wiki Plugin requires an Help:Action Page? with the content <?plugin PasswordReset ?> to be able the reset user passwords.
Any Administrator may reset (i.e. delete) any users password. The user may login with an empty password then or set a new one at the sign in page.
A normal user may only reset a users password who has his email address defined. For users with undefined email address you have to ask an Administrator to reset any password.
Authenticated users should change their passwords at their User Preferences page.
<?plugin PasswordReset ?>