Method 1: Via CPanel
Log in to your CPanel, scroll down to the Email section, then click on “Email Accounts”. You will see a list of your emails. Scroll down to the email you want to change the password, then click on “Manage” , enter your new password under “New Password” and click “Update Email Settings”
Method 2: Via Webmail
Login to your Webmail, click on your email address which is on the top right next to the Logout Sign, then click on “Password and Security”. Enter the new password and click “Save”.