AB powermonitor 3000 ethernet config

Hi guys, may be an obvious answer to this question but I'm a total noob to AB powermonitors.

Our IT department wants us to change IP addresses across the plant to new ranges. On one machine we have a AB powermonitor 3000, which the PLC communicates with over Ethernet IP. The original manual is lost and the only document I can find online only states how to structure an IP address and warns not to duplicate other addresses, but not how to set/change an IP address.
I can find the device in RSLinx, but there's no option to configure module, and I can open the web-based program, but that appears to be read-only. How do I change the IP address of this device? Am I missing something obvious?

you can do it thru keys located in front of equipment.
You can find right manual at:
http://www.rockwellautomation.com/global/literature-library/overview.page?

Sorry, I forgot to say, there is no display module. Only the unit itself. I'm hoping there's a way to plug in to the device to change the IP address as I currently can't see a way using RSLinx or via the PLC in Logix5000

We've found the display module, one of the engineers had it tucked away in a cupboard somewhere. Thanks for your time guys