Sending commands in the binary mode

I am in the process of developing remote data stations using the XBEE Pro XSC S3B modems connected to Silicon Labs C8051F120 micro controller. I need to be able to change the “MY” address on the modem in the binary mode. What is the proper method / flow to do this? I have tried waiting for the CTS pin to go low than asset the CMD pin and then send the binary string (0x2A 16 bit Address ox08) to no avail. What is missing?