Can anyone tell me where can I take a shuttle bus to Guangzhou Baiyun airport at about 5.00am.

Hi, you can walk from East Railway Station to Citic Plaza at No. 233, North Tianhe Road to take shuttle bus line 6. However, it takes around 45min to the airport. Then the time is to tight for your check-in process. Therefore, it is suggested to take a taxi in the early morning to arrive at the airport at least 1.5-2h in advance.