You can take subway Line 1 from Wangfujing and get off at Fuxingmen. Transfer subway line 2 and alight at Jishuitan.
Walk about 550 to Deshengmen and take bus 919 to Badaling.

Get off bus 919 at Changping and transfer 314, you will get to Ming Tomb.

Hey,
Beware of touts at Deshengmen Bus station. The fare to Badaling by 919(Express) is only RMB12 and RMB8 for 919(slow).I would suggets you to take the express.There are many buses with No. 919 to different parts of BJ. Please inquired at the counter before getting into the bus.