Guangzhou South Railway Station to GZ Railway Station

Hi, I arrive at GZ South on Sunday, 21:00, but I need to get to the Main GZ Railway station, where I leave for Changsha. I have two questions: the metro line 2 can take me there If not, how can I make it? Second question: Can I make the transfer in 2h30min?
Thanks in advance for any answers!! Best wishes!