If you already know this basic point please forgive me, but you do say you are a newbie.
You must of course first 'own' the IP numbers, you cannot assign an arbitrary number on a public network. If you rent/lease your Raq from a hosting company, tell them you need some new IP numbers and ask them to assign them.
For the new ip numbers to work, the DNS must also be set up to point the sites at them. If you are doing your own DNS, this is straight forward. Just use the numbers required instead of your shared number. If not, ask whoever does your DNS to set it up.