I seem to remember using a XBIB-U-DEV USB interface board with the X-CTU program to configure the XBee devices as coordinator, router or end devices and then configuring the device mode etc. If you do an internet search you will find lots of tutorials on X-CTU and XBee.
getting one of my old XBee series 2 out I downloaded X-CTU from Digi International - Making Wireless M2M Easy
connected a serial cable to a XBIB-R-DEV board and installed and ran X-CTU
using default serial port settings (9600 baud etc), clicked the Enable API box and clicked Test/Query and it found the XB24-B modem OK
I then goto Modem Configuration and can Read the current configuration (in this case a ZNET 2.5 ROUTER/END DEVICE API) and can load what configuration I require (coordinator, router, end device, etc)