Walk to the mountain back parking lot for bus no.919 fast which runs back to the downtown area and then get off at Xiguan Huandao. Afterwards, walk along the square at Xiguan until you reach the station for bus no.314, direct to the Ming Tombs. Or you can just take a taxi after you get off at Xiguan Huandao. It takes just the starting fare to reach there, or within twice of the starting fare to reach Dingling and Changling. Do not pay higher than that.