1) you have to have pure water or something with really low contaminants.
2) cool it to the above -21C
3) be very careful with it. If that person where to shake it or drop the bottle, the water would freeze inside the bottle.
4) pour it out.

Believe it or not, water wants to stay a liquid. Hence, if you take water that has no contaminants, you can heat it to very high temperatures without it boiling (which is why you never, ever microwave distilled water) or freeze it to very low temperatures without it freezing solid. But as soon as you add a contaminants, such as sugar or bubbles, the water is forced to go into a different state (gas or solid).