Breaking the fianchetto
The fianchettoed castle (pawn on g6, bishop on g7 in front of the king) is solid… as long as the g7 bishop lives. That bishop defends every dark square around the king: h6, g7, h8. That's why the recipe always begins the same way: trade it.
The classic three-step plan: (1) Bishop to h6 to trade the g7 bishop. (2) Push the h-pawn to h5 and capture on g6 to open the h-file. (3) Enter with the queen and rook down the open file to h8.
The g6 pawn has a second face: it's a “hook”. Your h-pawn reaches h5 and will always have a capture that opens lines. Without that hook (pawn on g7), opening the file is much harder.
This is the setup of the famous “Yugoslav Attack” against the Dragon Defense: opposite-side castling, you attack via the h-file and the dark squares. As Fischer said: “sac, sac… mate”.
Guided example
You play the pattern's moves; the tutor comments on each step. If you stray, it rewinds and you retry.
Practice: execute the pattern
Against the engine, with an adjustable defender level. Win the position to mark it as cleared.