How to use the model?

This model is just ready to be used. Just Open the file and you will find in the layer #1 the finished model. It's a single object so you will find easy to manage.
The center of the object is located at the center bottom of the model so also is ready to be transformated in any way preserving the right sense of movement and physic.

What about the transformations?

It has all the transformations applied to the obData
(Loc, Rot and Scale) Also it's located at the 0,0,0

I have a external animated scene, how do I link this prop?

It's easy! From your animated blend scene go to "File" - > "Link" (CTRL+SHIFT+O) -> Select the RocketShip.blend -> Inside the file RNA choose : "Object" -> then click the name of the only object on the file :"BedRoom". And be shure ,before you click on the "Link from Library" Button , to check the "Link" option (if you want to keep the relation) or uncheck it if you want a local copy of the model.