Rinse Screw Cap, glass tube with distilled water and add 25 drop of Reagent COD TK 1.
Now add  2 ml Water sample with help of syringe (or Pipette) in to the above glass tube.
Take Reagent COD TK 2 in a plastic tube up to the neck (3.5 ml) and transfer it to the above sample solution tube . Close the cap tightly . Mix Well by swirling  (Use of safety goggles and hand gloves is recommended )
Take approximately 30-40 ml of paraffin wax  in 100 ml glass beaker  hit it on a hot plate till temperature up to 150 degree centigrade. (Use Thermometer).