Don't worry. When you get off the bus, you can see many vans there. There are cable cars there to help people up to the Great Wall in Badaling.

Thank you for your reply Mr. James. We will be going to Mutianyu, not Badaling.

So, if I understand correctly, there are plenty of taxis waiting at the train station and you just get into one? I also want to know what a reasonable price is to pay for a taxi? Is it very far from the train station to the Mutianyu section of the Wall?

Oh, yes. Sorry. If you want to go to Mutianyu, you should take bus 916 at Dongzhiment and get off at Huairou. Then hire a van or taxi to Mutianyu. You want to take a taxi from Beijing railway station to Mutianyu directly? I didn't try this and I have no idea if the driver would go there from the city center. Most travelers would take the bus to Huairou and get off at Qingchun Lu Beikou and then take a taxi or van to Mutianyu, 40yuan is enough for the taxi fare.

You can also take bus 936 directly from Dongzhimen to Mutianyu Great wall