The most convenient way is to. BTS Skytrain and Taksin station. After that, Chao Phraya Express boat to THA Chang Wang Luang at the Grand Palace, which is located not far from the port.
the most convenient route is a BTS Skytrain station, and go to the Taksin after a Chao Phraya Express Boat to go down to the Tha Chang Wang Luang Royal Palace, which is not far from the port.