If your back is turned towards the bus station or aYa services turn left and walk down walking street to the river. Cross the bamboo bridge and turn left. Follow the dirt road past Pai Loese till the end of the road and turn right. KK hut will be at your left hand side after about 300 meters.
If you come from the direction of Chiang Mai you'll pass two gas stations on your right hand side. Next you'll pass the police station also on your right hand side. Take a right at the traffic lights. You'll pass a high school with a football field. Cross the concrete bridge and turn left. After about 1km you'll pass Darling viewpoint (a guest house). Take the first dirt road left (there is a yellow sign with KK Hut on it) and KK hut will be on your right hand side after 200m.