What was found
AIRCRAFT 395, AIR TURNBACK TO DEPARTURE DUE TO THE GREEN HYDRAULIC SYSTEM LOW ECAM MESSAGE APPEARED 45 MINUTES INTO THE FLIGHT AT FL370, RESERVOIR SHOWS HALF EMPTY, ALL GREEN PUMPS TURNED OFF. FOLLOWED MANUAL GEAR EXTENSION AND OTHER GREEN HYDRAULIC SYSTEM OUT PROCEDURES. REPLACED GREEN SYSTEM HP MANIFOLD PLUG PACKING.