1- To Change your password via webmail, go to your webmail URL.
2- Enter your full email address and current password and click the login button:
3- click on the drop down menu:
4- Click on password & Security:
5- Enter New password twice to confirm , click save button and you are done.
6- You can logout or choose a webmail application to use your email.
If you need further help,please send an email to support or open a support ticket.