If you have a user who does not have an email associated to their account, you won't be able to use the standard resetting of their password.  In the below example we will change the password for SampleAgent1.

1.  Click the Settings then Manage Users

2.  Search for the user and click the user name to edit.

3.  Click the 'Reset password'

4. Type in a temporary password.  Once the user has logged in with the temporary password, they can change the password within their profile menu.