Complete the indicated task to unlock the corresponding mission.

"Deadly Xin" mission: Unlock the Diamond Pillbox, Golden Binoculars, Jeweled Bong, Jeweled Key To The City, Platinum Syringe, Silver Titanium Briefcase, and Wooden Spoon trophies. Find the two hidden Lions of Fo. Register online at the Rockstar Social Club then sync your DS with your account through Wi-Fi. You will eventually get a mission email from Xin.
"Xin's Of The Father" mission: Complete the "Deadly Xin" mission and have no wanted level.