You will be able to make changes for a $30 fee up until your scheduled time of departure.

You can self service change your ticket date/time by logging in to view your ticket at Burner Profile https://here.burningman.org/my-tickets/login and select exchanges.
Then you can follow the steps in: https://support.showclix.com/s/a/Self-Service-Exchanges-Step-by-Step

If you are changing your route, switching cities or switching directions, contact us at burnerexpressbus@burningman.org