Take the Tsuen Wan Line (red) (to Central) for one stop to Prince Edward, then turn to the Kwun Tong Line (green) (to Tiu King Ling) for two stops to Kowloon Tong, then turn to east rail line (sky blue) (to Lo Wu and Lok Ma Chau) and sit at Lo Wu.
Note that east rail line is on the ground, as if walking upstairs. In short, some stations may need to get on and off. Look at these signs or ask yourself.