From west station to north station, Kunming

Well, you've made a correct search. The bus from Dali will arrive at the West Bus Station. Take a taxi to the North Bus Sation within 25min or around. There only one bus is on schedule for Guizhou Weining, ahnd it leaves at 12:00 every day. It takes around 7h and costs CNY120 per person.

The public transportation between the two bus stations is as follows:
take bus no. 80 to Shuanglong Shangcheng. Walk to South Ring Road (Huancheng Nanlu) and take subway line 2 to the North Bus Station directly.