7.1, new install, picking up old username for database

I am installing my app to a new php 5.4 Centos 6 server.
I’ve gone thru the steps, but when I startup my app via the url, it says it can’t login to my database using root, which is correct, because I now user a different username.
I never get to the screen so I can setup the database for my server.
How can I either force that screen so I can put the user I want to use, or where can I manually change the username it’s going to use?

Thanks

Try: …/_lib/prod/lib/php/nm_ini_manager2.php

I ended up doing www.mysite.com/_lib
and got it going.

Then had an issue with pdf generation because I’m on 64 bit linux, but I think I got that working also.\

Thanks
Alan