Take 4 litres or 1 gallon of skim milk
Heat to 160F at a medium temperature stirring constantly (or so)
Once it has reached 160F remove from heat and add 3/4 cup of white vinegar.
Stir for a minute. It will separate into the curds and whey.
Strain the curds and whey through a cheese cloth getting out all the liquid. While you rinse in cold water (it will be hot)
You are left with a ball of cheese curd.
break into small pieces and store like cottage cheese.
Good luck!
(I got this from Good Eats)