If you have completed your declaration and wish to make changes to your course you'll need to complete the online change request form or collect a Change of Course form from the University Information Centre. See the Changing your course page for more information on how to do this.
If you wish to change your programme (i.e. add, drop, or change qualifications, whether or not any papers are being changed) you will first need to apply via eVision for each new programme.
If you haven't completed the course enrolment declaration you are still able to make changes to your programme of study through your eVision Portal.