Clear stage to execute next action?

Hey,
If you know, can you pls tell where to find out how to clear the stage of everything I have loaded it with. This would be done upon click of one of the buttons I have on the stage. That button also needs to execute a different class I have programmed. You can even just tell me what to search under to find out this data.

Explanation: I have 2 different classes. Buttons class and Videos class. Buttons class loads the stage with 9 different buttons. Each button is supposed to lead to its own video. (I have the buttons ready with programming to load the video and all of the programming works).

The Video class loads the video onto the stage and has the controls for it to play, pause, stop etc (works pretty much…).

Now, I am not sure what code to put under each of the buttons to clear the stage and load the Video class. If you need me to explain more/differently pls let me know.

Thanks for any help!!!