Ven. Ananda said: "Friends, whoever — monk or nun — declares the attainment of arahantship in my presence, they all do it by means of one or another of four paths. Which four?
"There is the case where a monk has developed insight preceded by tranquillity. As he develops insight preceded by tranquillity, the path is born. He follows that path, develops it, pursues it. As he follows the path, developing it & pursuing it — his fetters are abandoned, his obsessions destroyed.
"Then there is the case where a monk has developed tranquillity preceded by insight. As he develops tranquillity preceded by insight, the path is born. He follows that path, develops it, pursues it. As he follows the path, developing it & pursuing it — his fetters are abandoned, his obsessions destroyed.
"Then there is the case where a monk has developed tranquillity in tandem with insight. As he develops tranquillity in tandem with insight, the path is born. He follows that path, develops it, pursues it. As he follows the path, developing it & pursuing it — his fetters are abandoned, his obsessions destroyed.
"Then there is the case where a monk’s mind has its restlessness concerning the Dhamma [Comm: the corruptions of insight] well under control. There comes a time when his mind grows steady inwardly, settles down, and becomes unified & concentrated. In him the path is born. He follows that path, develops it, pursues it. As he follows the path, developing it & pursuing it — his fetters are abandoned, his obsessions destroyed. AN4.170
This is the basic mechanism. The rest of the Noble Eightfold Path work together with the meditations, and contemplations. The outward manifestation might be different according to the teacher like their are different car manufacturers but all use the same internal combustion engine (if we set aside electrical engines for a moment). All the descriptions of stream entrants are qualities emerging from the same underlying process. These may vary from person to person to some degree but not massively I would think.
With metta