Moving from subdomain to main domain

Hello everyone!:)

I have been working on my new college blog bmcunited.org, I didn’t want the visitors to see things while I was working on the design and content of the blog. So, I created a subdomain test site (testing.bmcunited.org/wp/).

Now I am almost done with the design and development of the blog and I am looking forward to launch the blog on New Year’s night.

I really have no idea how to move my wordpress from subdomain (testing.bmcunited.org/wp) to main domain (bmcunited.org) name.

PLEASE HELP!