XBee - Firmata modifications

Hey everyone!

I'm trying to implement Andrew Rapp's Arduino libraries for the Xbee into the Standard Firmata, but I don't know where to begin!

(GitHub - andrewrapp/xbee-arduino: Arduino library for communicating with XBee radios in API mode)

Basically, we need to use Mr. Rapp's methods for writing to the serial port since we're using the XBee's in API mode and we can't figure out where to replace what...
(We're using an Arduino FIO)

Can someone help?

If you'd like more detail, ask away!

Bump.....help anyone?