This method is simple what is needed is 2 steel drums preferably lined, large cooking pots will work a shovel some firewood or other heat one long piece of sheet metal and about 20 concreate blocks or a mud wall and any water source preferably freshwater from a river or lake or even rain water.
As we all know sometimes you have to save your selves and some people need this kind of thing for daily life in third world country's,even in the U.S during natural disasters a temporary solution is needed.
Step 1: Step1
first dig a small whole and enclose the whole on three sides with either concreate blocks or a mud retaining wall for insulation and set three blocks/Rocks around the whole to hold the heated drum above a fire.
Step 2: Step2
Now arange the drums in place add the sheet metal, just lean it in till it locks in place, curve it a bit so it will retain the steam more giving it time to form droplets and cool and run down the sheet metal into the catch drum. The cold catch drum is where the drinkable water is and the hot drum is where you add the river water to be distilled.
I know this is simple not to needed in most cases but isnt it beter to be over exposed than unprepared.
This would also make an excelent science demo project for kids.