Each dashboard user can either set or delete their own triggers, and admins can also do this on behalf of other users. You can do that through the Triggers Dashboard or by editing Triggers on a particular stream.
1. Log in to your dashboard
2. Go to the stream that you wish to remove trigger from
3. Select EDIT TRIGGERS from drop down on the right-hand side.
4. Find the trigger you would like to remove in the list, and click on actions.
5. In the drop down list select Delete. It will ask you for a confirmation and after you confirm ("yes, delete") this trigger will be removed.