IP change in Plesk is not trivial task)))) even if you read all the
documentations 🙂
So if you decide to change IP in Plesk but you can not do this via
Plesk panel you should:
1) read this KB http://kb.parallels.com/en/943
2) add new IP
3) do the trick in Plesk DB
mysql -u admin -p`cat /etc/psa/.psa.shadow
mysql> show databases;
mysql> use psa;
mysql> show tables;
mysql> select * from IP_Addresses;
Now you should see a list of IPs you should delete new IP
mysql> delete from IP_Addresses where id=
mysql> quit
/usr/local/psa/bin/reconfigurator.pl