you will be picked up at the Exit A National Agriculture Exhibition Center metro station(Line 10) at 8:00am(recommended to leave at 8:00am cos it will be much less traffic on the way to there and the way back to the city meanwhile much less tourists on the Great Wall, you can avoid the queue for everything and enjoy the view there better but if you don't want to leave too early then it is flexible) in the morning by the driver, he will take you to Jinshanling Great Wall,the driver will wait for you at the point where you hop off the car when you return,this transportation service only including transportation,nothing else so you need to buy tickets, food ,etc by yourself, you will have about 3 hours on the Great Wall,after that the driver will drop you off at the same point where he pick you up