Log into ShowingTime (either from the icon in the Quick Links section of the SmartMLS Member Dashboard or by clicking ShowingTime in the External Links widget on the Matrix homepage.
Click Showings> I Have Requested:
Click the View/Modify button next to the correct listing (on the far right side):
Click the Cancel Appt button in the bottom right:
You may also click Reschedule to try to set up a showing appointment for a different day/time.