Hi,I am planning a business trip to Guangzhou but will be landing at Hong Kong.

I plan to stay a few days to visit the city before heading to Guangzhou. I will arrive on a Saturday ica and will be staying somewhere in Kowloon and leave for Guangzhou on Tuesday, I have to be there by 11am.
What is the best option? Plane, Ferry, Limo, Bus or train ? I want the easiest and not more than a 2 hours trip.
Thank you