Xbee Broadcast With arduino mega

I am working with xbees. Configuring xbee to the broadcast port solves the problem earlier. However, now i am using arduino mega and there is embedded xbee shield inside it . How can i configure to broadcast mode in the arduino mega board.

Thanks!!

arduino mega and there is embedded xbee shield inside it

This sounds like you bought a specialized Mega so why not ask the source of how or if it can be done?