HT1338: OS X: Updating OS X and Mac App Store appsLearn about OS X: Updating OS X and Mac App Store apps
Currently Being ModeratedOct 12, 2012 11:17 PM (in response to Designer in NY)
What IP address are you trying to change: the new iMac, the old iMac, the Time Capsule WAN side, the Time Capsule LAN side?
Generically, Mac OS X IP addresses are controlled in System Preferences > Internet & Wireless > Network.
Time Capsule IP address are controlled in Airport Utility.