Stormworks doesn't have built in Video Switch-box without making a microcontroller, I saved you the hassle.
Very simple setup:
Connect the "First Video - On" to the video in which will turn on once you press the switch button.
Connect "Second Video - Off" to the default video which will be shown by default.
Connect the "Switch Signal" to the button that will switch the videos.
If you need anything, message me in the comments.