When originally looking into wireless bootloading using XBee, I found this article on the Ladyada site extremely useful. Here are the steps you need to configure for Firewing. It assumes you are using the X-CTU configuration software, connected to a Sparkfun Explorer Board. Please note that an equivalent host board should work just as well.
This should be a four digit hexadecimal number. Both the transmitter and receiver must have matching IDs
Interface Data Rate
The Firewing XBee loader uses a baudrate of 38400
This value is taken directly from the Ladyada site and works very well with the Firewing loader. It basically determines the timeout value between transmission characters.
D3 Input / Output Pin
This pin is connected to the Firewing XBee software reset circuit, so needs to be configured as an output.
Again this value is taken directly from the Ladyada site and works well. It prevents data appearing on the serial line and just toggles the data pin (D3IO)
A value of FFFF will match all XBee moule input addresses.
Don't forget to press the X-CTU "Write" button after making all of the changes!