As you are not changing the Firewalls here there is no need to use any uploads. But as precautionary, keep tftp copy of current working running config from fw handy.
Now as far as the names, yes.. just changing names will not work. My preferred method (although not the best), I copy the config to text file and edit (with new IPs) wherever necessary. I keep (names, static, route, tunnel etc) old config lines with 'no' key word form and new config lines as well so that I copy/pastethe config during the maintenance window. That saves lot of time incase of any unforeseen issues and needs time to t-shoot.
Also, Within the maintenanace window I did it phase by phase. (1. Internet 2. DMZ access 3.VPN changes etc).
Make sure you clear the arp tables on external switches and Xlates on ASAs after changing the IPs.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
[toc:faq]Introduction:This document describes details on how NAT-T
works.Background:ESP encrypts all critical information, encapsulating
the entire inner TCP/UDP datagram within an ESP header. ESP is an IP
protocol in the same sense that TCP and UDP are I...