Hi, I want to get from Yuanyang to Guilin in mid November.

I'm afraid there is no direct long-distance bus from Kunming. To save time, direct flight is the best way; and train comes first when considering saving money. If you wanna have another option, transfer is needed. Take a train to Guiyang first in 8h and transfer to a high speed train at Guiyang North to GL in around 2.5h.