You're right, they pulled the script in 6.6.0.3.
Really this all depends upon how your SPA was installed. If the SPA was installed by FQDN (the highly recommended method) then no need to do anything. Just change the IP on the NIC and ensure DNS/hosts files are up to date. You can tell how the SPA was installed via:
# cat /Storage/etc/topology.ini (may need to decrypt it first)
or
# /opt/pddb/bin/psql -U pddb ca -c "select * from agent where isserveragent=1"
....and note what the hostname is.
If however the SPA is installed via IP address, then what I would do is get a copy of convert_to_hostnames.sh from the PD66 install media, put that in the /opt/pdconfigure/scripts/support directory, make it executable and use it to convert your SPA from IP to FQDN.