How To Make Door Entity

[trancedj]

I've imported a door mesh into modeleditor, I would like to know how to add properties to transform a simple door mesh into a door entity
I've tried to do that, but I cant interact with it.
I saw the video "From 3D model to interactive door in HPL2 engine", it's too fast for me to know the steps for creation door entity.
May be tutorial would be appreciated