Watch this video for a step by step process on How to Force a User to Change Password from WHM
As a WHM user, you can urge or force your hosting client to change his/her password. The system will prompt them to change their user password once you do the configurations we have described in this tutorial.
To Force a User to Change Password
1. Log in to the WHM panel with your root account.
2. Select the Account Functions option from the navigation menu.
3. Click on Force Password Change.
A list of active user accounts on your server will appear.
4. Select the box under the Forced? column for user/users to prompt them to change their password.
5. Click the Submit button.
That is how you can urge or force your clients to change their password via WHM.