Go to http://mail2.appsmail.com. Then type in your full email address and password in the appropriate fields, then click "Login".
After logging into your account, click on the "Settings" menu in the upper left corner & select "My Settings"
Type in your "Current Password" (the one you used to log into the account with), and your "New Password" (the one you'd like to use in the future). and click on "Save" in the upper left.