Hi we are staying near Heilongtan in Kunming and want to go to the western hills by bus, is it possible?

Of course, but there is no direct bus. You can take bus no. 9 at Heilongtan bus stop to Ciba Station, where transfer to bus no. 115 to Jinhuapulu Station. At this station, you can take bus no. 18 and get off at Gaoyao Station. Then you can walk to Western Hills Scenic Area.