Trying to figure out how to make the little door that the chickens go from the coop to the run. I have an aluminum 4x6 shed out into a 18x18 run. Planning on doing DLM, but what do people do with the litter when time to clean out and replace? How far off the door should roosts be set? Any need of a walkway up to them or the nests? (mine are about 2-2 1/2 feet of the floor )