Take the vital point on offence
Killing is the vital point of Lesson 8.3 seen from the other side of the board: occupy the one point that keeps the eye space from splitting, and the defender can only ever make a single eye. The typical mistake is pushing against the surrounding wall from outside — each push lets Black answer calmly inside, take the vital point himself, and live while you have gained nothing. Attack the space where the eyes must be born, not the stones that guard it. Black's space here is a straight three with its centre still open: whoever plays it first decides, exactly as in 8.3. White to play: strike before Black does.