Train from Guangzhou Pullman hotel to YMCA Salisbury Rd Hong Kong

Hello,
Can someone give me detailed directions how to take the train from the Pullman Hotel in GZ to the YMCA by the Star Ferry. I understand the train is the best but I cant figure out what train and if it is direct to Hung Hom or do I need to change trains in Kowloon Station? How to get from Hotel to GZ train and Hung Hom to YMCA?