Kunming East Bus Stop to South Bus Stop

Hi there, I'll be taking the 7:00am bus from Luoping to KM and hoping to catch the 12:30pm bus from KM South to Yuanyang Xinjie. Could you please advise if this is doable? And what's the most cost efficient way to get from KM (I'm assuming KM East since I am coming from Luoping?) to KM South? Thank you!