From VG247: “Agent 47 is off to the races and hes planning on making a killing. Heres how to get a Silent Assassin rank in Hitman 2s Miami mission.
When you start this assignment, instead of heading through security and getting frisked, make your way into the underground tunnel to your left, past the busker, and out by the research centre with the chrome dolphin fountains.”
Source: N4G PC Hitman 2 Miami – how to get a Silent Assassin rank