Changing Word Press from Sub Directory

Hello,

I installed wordpress in a sub directory of an existing website so that I can develop a new design. I have completed the development but now I want to make the sub-directory “live” so that when people type my domain name, they will get the contents of the sub-directory where my new design is instead of the existing old design.

My ISP is not being helpful and my search on the internet has resulted in many options (all with different ways of going about it) so I was wondering if anyone can recommend an official www.remarpro.com article or another good current article on how to do this so that a newbie might understand. So far everything about wordpress has been relatively easy and I know that this is not strictly a wordpress request so any help would be greatly appreciated.

I have a cpanel account if this helps.

Kind Regards,
HS