On the signup page, click on the Forgot your password? link and enter your email, and we'll send you instructions to reset your password.
To change your existing password, go to My Account, select the tab 'Account Settings' and click on the Change your password button.
The instructions here are to reset your credentials at the TagoIO admin, if you are looking for a reset/change password for you or your users for the TagoRun application, you need to access the User Management.