Hello! Ok, so are you trying to open the example project itself, or migrate the contents into one of your own projects?
To open the example project, the easiest way would be to go to the extracted folder location and double click the project file itself (BallisticsVFX_1_0_5.uproject). This will then load up the project with the correct UE4 editor version… it should also then populate the project into your project browser for easy access next time. Let me know if that helps or not 