It not rocket science.
You insert two instances. Associate each instance with a layer of it’s own.
A “Closed” layer, and an “Open” layer.
The “Open” layer is OFF in the “Closed” scene. Update the layer.
The “Closed” layer is OFF in the “Open” scene. Update the layer.
Now switch to the “Open” scene. Select the component instance and right-click it, choose “Make Unique”.
(This creates a unique component definition for this instance, so you can edit it without affecting the “closed” one.)
Now activate the DC Interact tool, and open the door on the (now unique) instance.
Save the model.
Now switching between the two scenes, will show one with door closed, one with it open.
Here’s an example, using the sampler Mailbox component:
Mailbox_2_door_positions_2016.skp (135.1 KB)
Notice that there are scenes for use with LayOut, and that there are two scenes for printing with the doors in both positions.