Simply copy either the open or closed dome 3do into the root directory of the night track. This will make the dome in an open or closed state. Please note this is only for the night version of the track. If you use these 3do's for the day version it will look a little off as the lighting with a closed dome has sun still shining through, it will appear unrealistic.

To revert changes simply remove the 3do from the track directory.