Imagine a rectangle with an open front and a roof - this is your goal and is why a child's dollhouse is perfect.
Step2
Empty the dollhouse completely, taking care to cushion breakables.
Step3
Remove everything you can, including curtain rods, second floors and plumbing fixtures (if it has a lot of built-ins, see Tips below).
Step4
Make the dollhouse look as simple and as rustic as you can. You may want to lay some branches on the roof to mimic thatch, surround it with dry grass or straw (don't forget to scatter some on the floor - this is a stable, now, remember), even wrap it in burlap or linen.
Step5
Add some nativity scene figures and some plastic animals.