[justin.knox]

CLISH is the way to do this from the command line in IPSO (3.8.1 and 3.9 anyway). You can find the documentation for these commands in the IPSO 3.9 CLI Reference Guide (Chapter 2).

Before changing your running config, I'd suggest making a backup using the save command.

you can issue the command show interfaces to see all interfaces and their configuration (physical and logical).

find the logical interface you want to modify
issue the following delete interface command to remove the IP address from the logical interface:
delete interface log_if_name address ip_address

then issue the following add interface command to put in a new address
add interface log_if_name address ip_address/mask

once you've made your changes, don't forget to save the configuration with save config

hope that helps.
--Justin