Hongkong / Kowloon Station?

Hi,
1. after take airport express to Kowloon station. May i know how to get MTR Tsim sha tsui? Or is Kowloon station itself connect with MTR Station?

Which way easier from Hongkong station to the MTR or Kowloon?

2. I'll transit for half day only.
If i have ticket for kowloon station, is it applicable for me to depart from hongkong station instead when am bout to going back to the airport later?
Or i should go back to kowloon again to going back to airport?

Thank you in advance! :)