the breathing sequence for Heart Tantra, additional explanation

for man, (women start breathing out with opposite nostrill)

breathe in with both nostrills, then closing the right one, breathe out the red prana, then breathe in again with both, close the left one and breathe out the white prana, repeat this sequence 3 times alternating the nostrills, then breathe in and out with both nostrills - 3 times repetition with details as described in Heart Tantra text,