To change the password for an email account in cPanel you will need to login to your cPanel account and locate Email section as shown in the below screenshot.
From the top, select Email Accounts that is located on the left side of the screenshot, once you click it a list with all email accounts will be displayed as shown in the following screenshot. If there are no email accounts this means that you do not have any email accounts created with the associated account. Follow this documentation on how to create an email account in cPanel
In the above screenshot it shows the email email@example.com On the right side it there is a button called MANAGE, click on it and you will be redirected on the following page
In the password box type the new password and then click UPDATE EMAIL SETTING
If you need any help please do not hesitate to contact us. Our team is available 24/7 via our Chat or via ticket submission.