May I know the sleeper bus from Kunming to Ruili, where will it stop.

You can take the bus at KM North Bus Station, and the bus will stop at Ruili Bus Station at Nanmao Street. Your hotel is about 500 meters far from it, you can walk along the Nanmao Street eastwards for 120 meters and turn right to the Changle Street for 400 meters to your hotel.