Copy and Paste from Different Movies
If you need a scene from a movie you've already created, instead of redoing the entire scene, cut the work in half and learn how to copy scenes from one movie and paste them in another.
First have both movies open in Demo Builder, you will see the movie titles in the Movie panel to the left in Thumbnails view. Select the scene you want to copy, right click and select Copy or press CTRL+C.
To paste your scene, select the movie you would like the scene to go to. Then in the Thumbnails view of the movie right click and select Paste or press CTRL+V. The scene will now be in both movies.