You can choose to keep the stained glass windows or cut them out. Equally you can go at it with a craft knife or a Dremel multi-tool and make a ruin. You can even print an extra set onto card and add some of the decorative details onto the paper so it has a little more depth, your choice.
The roof section also comes with a Standard Manifold Coupling illustrated on top. You can keep it as is or cut it out to add any other modular plugs. Additionally it will provide access to the first floor, which is also available in the ST, should you wish to add it to your model.
Essentially all you really need to do is print these, stick them to foamboard and cut out. I might suggest using A4 sticky labels for the printing, then either bevel the edges to 45 degrees or remove an interior 5mm strip so the boards can slot into each corner - simple!
To access the full STC please point your Cogitators here, be fair warned it is 44MB in size [I make no apologies for this, I could probably render it as a .jpg but what the hey?!]:
As you can see from the teaser picture below I have some other sized versions which are awaiting completion and a different colour of building. In truth I have five different styles so far, I think they get better as I developed them.
As you can see I started to get adventurous, this plan will be slightly more complex because you can print the windows onto printer acetate, another copy onto card and another onto foamboard. Remove the windows on the foamboard, add the window sheet, then use the card version to add some details!