Injecting - Need Best step by step information on injecting Heroin

[methadone_lad]

my friend is 21 is a heroin addict he is on methadone and other tablets,he has smoked for years but likes to inject,when he has been injecting he has been getting other experienced people with him to do it,he just needs the right advice when he gets a street bag ie (0.3-0.5) of a gram,how much water to put in the cap ie a full pin of water or 2 ect??,and how much citric acid out of the little sachets,and how much does he fill up on the pin when its cooked up to inject? ie 0.50mil ect,and how many hits can he get out of 0.3-0.5 gram bag ie (2 pins full to 0.70 out of a bag) or 3 pins full to 0.50 out of a bag please please help in detail as he could put too much into a pin and od,thanks