Change the domain name of a php web script

I buy a web script and I will install it on my host server on which I have two domain accounts, and the domains are resolved on the server.
I asked the developer if I decided to change the domain name, at some point after installation, what I could do, and I was told to edit it in the config file .php.
After making this change and the necessary changes in WHM / cPanel, what more than copying the database, what would it take to get a complete domain change?