Model changing - Instance swapping ... how to do this ?

Hello everyone .

I have a question , i see many more of videos like that :

YouTube - The Hillsbrad Dream

That's model changing , or instance swapping . All right , but can i do that ?

How to do something like that , on an Ascent server ? I don't understand ... i search everywhere , but i find nothing .

Please , i need a little help about this .

Thank you .