I created a custom html website in a subfolder. The current website is in the public_html folder and is Wordpress.
I can't remember or find any help on moving this site to the main folder and pointing the domain to the index.html file.
I know it can't be as easy as just copying it.
Rename the index.php to oldindex.php
This will stop the wordpress from showing up
Now simply drop the index.html in the directory and it will show not the wordpress website. Make sure you drop all the files for your new website.
You might also want to check out the .htaccess file for wordpress related parameters. If you are not familiar with the file, call GoDaddy and ask them to check it. The file itself is easily edited in Notepad (I use Notepad ++).
Hope this helps,