Change sceen in a demo

I have looked on the internet for a good exampel for a demo in OpenGL becouse I want to make a little intro telling the demo name and stuff and it should be playing for about 10-15 sec or somthing, then I want to change sceen and objects and start to render them as the actual demo, and after that I want to switch to a end sequense and then I end the demo.

How do I split it up i different parts like that ? and how do I tell The Programm it should stop and go back to Windows ?