How to get to Grand Mercure Hotel or Holiday Inn express from Beijng South Railway Station?

hi there, my friend and i will be going from Shanghai to Beijing via train. How do we go from the Beijing South Railway Station to the Xidan area? We are planning to stay in the Grand Mercure Hotel. Another option would be to stay at the Holiday Inn express at the downtown area. How do we also go here from the Beijing South Railway Station?

Many thanks in advance!! Cheers!