Grey Water with a pad

Can you tell me some information on how you would retrofit a home for gray water for the washer, and sinks. I would love to do the showers too but I cannot get them to touch a wall... these all touch an outside wall. This is not something I will be able to get a permit for but.. I am going to try it anyway. So any tips, helps or photos you have would be a great help. I havea pad and brick walls so tips on getting throught the walls without much trouble will be something big too...