Exam registration, cancellations, and changes are handled through your account on HUDHousingCounselors.hud.gov.
To change your exam delivery type, sign in and select Change Your Test Date in the Countdown to your Exam section of your User Profile Dashboard. Follow the steps under Reschedule an Exam to cancel your scheduled exam (the exam purchase will be refunded to the credit card used), then follow the steps to register for a new exam.
Be sure to review the No Shows and Cancellations Policy prior to making changes.