If you are switching to a new server within the current hosting provider or with a new provider, all that is required to do at Incapsula is to change the site IP address.
That is done accordingly:
2. Origin Servers tab
3. Enter the new server IP instead of the old one
There is no need to make any changes to the Incapsula DNS records.
The change is propagated to the various proxies and becomes active within a few minutes.