You are able to change your account password at any time. To do this, click on the Account Name button in the top right hand corner of your screen. This button will have your name or the name of the account. A dropdown list will appear. Click the My Profile button. This will open the Profile Account page. 

Inside the Profile Account page, click on the Password button on the right hand side of your screen. You will then need to enter your current password as well as your new password for your account. To save these changes, click the Change Password button.