Only Teacher, School, and District accounts have the ability to change and reset passwords. If you have a Student account, your Teacher can reset your password for you.
If you are logged in as a Teacher you can reset Student passwords, if you are logged in as School you can reset Teacher and Student passwords, and if you are logged in as a district you can reset School, Teacher, and Student passwords.
If you are logged in as a Teacher go to Students, and if you are logged in as an administrator go to Accounts. Both are in the Manage section. Next, search for and click on the account you need to change the password for.
Type the new password in the Password and Confirm Password fields and click Save.