Colocation change - What steps to take (and in what order)

Hi, At the moment we've a small cPanel cluster consisting of two colocated servers runnning regular cPanel (ns1 and ns2) and one VPS running DNS Only (ns3) for some years. Unfortunately our current colocation provider is going to stop in a few weeks and therefore we'll need to move the two colocated servers to another network and/or DC. In order to avoid as much downtime as possible (both cPanel colocated servers have active accounts on them) we think of moving the cPanel colocated servers one server at a time and the one running ns2 first. We've already created a list of things to do, but unfortunately we're not yet sure in what order to do them. Can you please advise: [quote] Old situation: **** Main IP : 1.1.1.1 DNS2 IP : 1.1.1.2 Dedi1 IP: 1.1.1.3 Dedi2 IP: 1.1.1.4 Network : ColoOld DC : UnChanged FQDN : server.domainname.ext New Situation: **** Main IP : 2.2.2.1 DNS2 IP : 2.2.2.2 Dedi1 IP: 2.2.2.3 Dedi2 IP: 2.2.2.4 Network : ColoNew DC : UnChanged FQDN : server.domainname.ext Things to do: *Blacklist check all new IP-addresses *New Colocation provider level = Set rDNS for new IP-addresses *WHM->IP Functions->Add a New IP address = Add the four new IP-addresses *WHM->DNS Functions->Edit DNS Zone = Change IP-address for server.domainname.ext WHM->DNS Functions->Edit DNS Zone = Change IP-address for ns2.domainname.ext *Registrar level = Change IP-address for ns2.domainname.ext *WHM->Server Configuration->Basic WHM Setup = Change to New Main IP-address (appears to be included in IP Migration Wizard) *cPanel License = Change to New Main IP-address *SSH = Change IP-address of server to New Main IP-address (what's the best way?) *Third Party Plugin License(s) = Change to New Main IP-address *WHM->IP Functions->IP Migration Wizard = Add the four new IP-addresses and continue (or one at a time?) *Shutdown server and move to new location *WHM->Service Configuration->Exim Configuration Manager = Add New Main IP-address to "Trusted SMTP IP addresses" and "Whitelist: IP addresses that should not be checked against RBLs" to other cPanel servers in cluster and remove old Main IP addresses *WHM->IP Functions->Show or Delete Current IP Addresses = Remove the four old IP-addresses
Thanking you in advance.