3 days to admire the wall

I have 3 days to admire the wall, I will be travelling from Beijing, my plan as follow;
1st day Beijing-Jiankou-Mutianyu
2nd day Gobeikou-Jinshanling
3rd day, jinshanling-Beijing,

question is after first day, if I get off the wall at Mutianyu, how can I go from here to Gobeikou if not using taxi?