VERY EASY.
You take a plastic container and fill it with ice. You insert into it a smaller plastic container which is filled with a mixture of concentrated nitric and sulfuric acid. You drip glycerine into the acid while stirring with a plastic spoon. The brownish colored liquid that forms on top is nitroglycerine. It is removed with a plastic ladle. It can be used "as is", or purified by passing it through activated charcoal. It is toxic even to breathe the vapors, so keep it on ice. I did it when I was 13 years old.