How do I get from Mt Huangshan and Hongcun from Shanghai?

From SH South Bus Station, you can find direct buses to reach Huangshan scenic spot directly.
From the attraction, there are direct buses to reach Hongcun at Nanmen Bus Station. If you travel with some other people, it is suggested to hire a car to reach the Hongcun directly and the car's fare is around 100RMB.
Two days are a little bit tight. If you have enough time, it is suggeseted stay one more day there.

Thank you Gordon for your response. I will look and see whether I can stretch to 3 days for this part of my trip.