It should be easy but I am brand new to WP and need help

Aloha
With help, I have just finished a new WP Enfold website.
My current non-WP website runs at https://www.kau-hawaii.com
We built the new WP website at https://www.kau-hawaii.com/wordpress
My hosting company is Hostway. they say online that they support WP, but when I called to get help moving the new WP site, they daid they can not help me. I have emailed them and have not heard back.
I have printed out the directions for Changing Your Domain Name and URLs.
The person who helped me build the website does not get involved with the server side, so I need to get help to do this on my own.
I did backup the date file and the xml file to my local computer.
So… according to the help instructions… the next step is to change the URLs. Then, I am supposed to go into mySQL and export the database and download site files and I am getting quite unsure and lost.
I know this is easy, but it is my very first time and I have read too much about how things can get screwed up and I feel like I need some hand holding. Thanks