Open Pokerstars client, select Help from the menu on the right, in the menu on the left — Contact Support, in the middle of the window there will be an Open Contact Support Form button. Select English, the Poker category, then Request Hand History Reports.
You can use this template:
Hi, dear PokerStars team! I kindly ask you to send my Hand Histories for the period from ______ to ______.
You should use HyperTracker to send history. Open the Verification tab, click PokerStars and past the link in the first field. Press Send.