First make sure that you are trying to log onto the Macci platform and not the Student portal.
You will see this login page:
If you have forgotten your username then you can refer back to the email you received when you registered on Macci for the first time.
You would have changed your password when you first logged in, but if you have forgotten what this was, you can click on the "Forgotten your username and password?" tab on the login page (as shown in the image).
This will ask you to add your username or email address to reset your password. An email will then be sent to you with a new password.
NB: Remember that all communication will go to the email address you used to register on Macci.
If you have changed your email address but not updated this with the ICB, then you will not be able to reset your username or password and will not receive any communication. You will then need to contact the ICB directly and or update you email address on the student portal.