Cover the windows in black card - doesn't matter how untidy it looks as long as you block out all the light.

Then using the pin make a hole- you may need to widen the hole -just widen it until you start to see the upside down image of outside and it will become clearer.

Enjoy the results, you can photograph the results if you wish- here is an artist that does that :

http://www.abelardomorell.net/photography/cameraobsc_01/cameraobsc_11.html