DMX-512 transmitted on a Ardunio to a Xbee

I've been tasked with the following.
Read in a DMX-512 light display controller input to a Ardunino USB. Then take this data, do some work on it, and transmit this wirelessly using the XbeeSheild to another Xbee Shield which will talk to a Second Arduino and then using the PWM output, turn on some lights etc.
My problem is that the DMX-512 will be being read in on pins 0 and 1 TX/RX and i also believe that the Xbee Shield will be using these same pins. Is there a way to use the I2C pins instead for either reading in the DMX-512 or transmitting the data to the ZigBee Module rather than using the serial pins?
Any suggestions would be GREATLY appreciated.
Thanks

You can jumper the Xbee to use a different set of i/o pins and use a software serial library to communicate with it. This frees up the hardware UART on pins 0 and 1 for your DMX device.

http://forums.fungizmos.com/viewtopic.php?f=6&t=4

Will