Hiking From Jinshanling to Simatai route

Hi! Please let me know if this is correct.
- from Beijing to Jinshanling: take the public bus from wangjing west subway station, and take the free shuttle bus from the bus terminal to the wall.

- back to BJ from Simatai: take tourist bus #2 and get dropped off at Xuanwenmen

How long is each bus ride?
What bus number to I take from wangjing west station?
If I am hiking from to Simatai, I heard that I have to take the stairs down at the 5th tower to the town of Simatai. Is that where the bus station for tourist #2 bus is?

Thanks!!