You can change your password within the platform by going to the drop down arrow by your username in the top right corner of the inbox.
Select My Settings and click on Change Password
If you're unable to login and use your email address as your username, you can click the forgot password link from the login screen to receive email instructions on how to reset your password
If you're unable to login and have a non-email username, you will not be able to use the reset password link. Instead, you will need to contact the administrator on your account and ask that they reset your password through the Manage Team setting in the product.