It is advisable that you change your password regularly to prevent your server from getting compromised.
To do this, first you need to be logged in to WHM then from the search bar on the top left of the screen, just type in “root”.
You will then see the “Change Root Password” option on the left pane. Click on that and the Change Root Password screen will show up. You may now proceed in typing your preferred new password.
You may also create a system generated password by clicking on the “Generate” button. Remember that you can set the criteria you wish to use to create the password by clicking on the arrow beside the generate button.
Once done, you may go ahead and click on the Change Password button on the bottom part.