I have to go from hong kong to shantou / shantou to hunan / hunan to beijing / beijing to hong kong.

1. From Hong Kong to Shantou, you can take long-distance bus at Sheung Wan, Connaught Road West (central police station after). It will take you to Shantou directly. The schedules are 09:10 and 15:10 with 5 hours' duration.

2. Well, Hunan is a big province in China. And it contains many cities and counties. Do you wanna go Changsha the capital city? If yes, from Shantou to Changsha, you can take direct long-distance bus at Shantou Central Bus Staion. Then arrive at Changsha South Bus Station. The schedule is at 09:40. Duration is about 15 hours.

Or you can go to Guangzhou by bus (5-6 hours) or train (7 hours), then change to a high peed train to Changsha (3 hours).

3. From Changsha to Beijing, take high-speed train from Changsha South Railway Station to Beijing West Railway Station. It takes around 7 hours on the way.

4. From Beijing to Hong Kong, it's suggested to take a direct flight. It spends no more than 4 hours in general.