You add it to the brake fluid reservoir bit by bit as each of the 4 wheel brakes is bled through to purge the old fluid. Without special equipment this is not a one man job
Manufacturers recommend that it is changed every 2 years which I think is too quick but its up to you
If you're that unsure about adding "break" fluid to a car, how much, what type, or why, suggest you take it to a garage who will do it for you, if it's necessary at all.
|I dunno, but |I think its called "Brake fluid" |You wont find anybody selling the other stuff. |Thinking about it though adding water to where the engine oil is would become |"Break fluid|"