How can I change an Xbee Router into a Coordinator using just some commands from another Router?

I have a mesh of three radios. I want to add more. Its not functioning yet but I wish to set it up and make them talk to each other using an Arduino at each of their ends. Obviously, one of them will be coordinator initially. What if this guy dies? In such a case, I want to make another Router the coordinator of this network and want to continue without problems.
Is it possible using any commands?
Thanks

If coordinator dies then you can add new module as new Coordinator of network or can opt for existing Router for this job.

Check “Replacing a Coordinator (security disabled only)” section here for details:
http://ftp1.digi.com/support/documentation/90002002.pdf