Hi, go to shanghai hongqiao airport. Take a flight to guangzhou first. And then there are long-distance bus to zhongshan from guangzhou baiyun airpor. You can take the bus at No 7 Gate of the Arrival Hall. The cost is about 65 cny and the duration is about 2.5 hours. The bus will drop you off at Season View Hotel and you just need to take a taxi there to get to Guzhen. Hope it helps!