Take option 1 (Wrok with TCP/IP interfaces)
Create a new IP
Delete the old one.
Each Ethernet card on the iSeries can have multiple IP addresses so you may not want to delete the old one right away.
From CFGTCP option 1 “Work with TCP/IP interfaces” you can change the entry for Autostart to *NO.
Other handy options are F11=Display interface status, 9=Start and 10=End
When you are changing or adding an IP address you may also need to look at options 2 “Work with TCP/IP routes”, 10 “Work with TCP/IP host table entries” and 12 “Change TCP/IP domain information”
To make other changes depending on your situation.