Shenzhen Airport to Hong Kong, mongkok area

Hi, I would like to require if let say I'm from bao'an airport and would like to go Hong Kong Mongkok area.

1) How should I go and is there any bus which could direct to Mongkok?
2) If let say there is a bus from bao'an airport to Kowloon, which part of Kowloon will it be?
3) For Kowloon terminal stops does it has any MTR or transportation nearby to go Mongkok?

Thank you.