Changing to root

Hi y’ll.
First things first I’m a novice treat me gentel.
Our website is hosted external
Our nettwork we run of our own servers.The website is using the same domain as our inhouse domain.
When our website was established it was created in a folder www of the root.
Seems that this is the cause that we can’t acces the site without using www
Been reading and tried some solutions so i could use just domain.no but can’t get it to work
I copied the whole site to the root changed the wp-config.php (grayed out in the dashboard) changed the settup with our hosting provider and in the DNS records waited and tried but couldn’t get up the site under domain.no
What do I do wrong ?
Rene