You can take bus no. 5 from Jingshan Park west gate to Drum tower directly, and then bus no. 5 to Beihai park. Houhai is just located at the bck gate of beihai. Finally, take bus no. 635 to nanluoguxiang.

This is a really good Day trip, but you would be much better off Doing it in this Order: Jinshan Park - Beihai Park - Houhai - Drum and Bell Towers - Nanluoguxiang. If you exit Jinshan park at the south gate, you can walk west to the south gate of Beihai park, then walk around Beihai to the north gate, which is on Dianmen West Rd (Dianmen Xi Da Jie) and right across the road from Qianhai (the first lake in the houhai district and the one with all the good restaurants). After Houhai, the drum and bell towers are only short walk (a few hundred metres). Nanluoguxiang is on Gulou East St (Gulou Dong Da Jie) and again, a few hundred metres walk away. There are lots of cafes and restaurants along the way if you need a rest!