if its computerized, then Toyota dealers would be the best.
For LCD and back Camera, it hardly cost around Rs. 1500. But technicians always ask for 5~7,000 depending upon your personality and car model.
I have contact number of two guys.
malik tahir awan
he runs car show room in johar town. he sells JDMs and has couple of guys who do this job in his show room.
Convince him with conversation and he will help.
Mr. Irfan. He has shop in Hall Road in the basement of very first plaza and is deals with Navigations, Cameras, audios, etc.