How to change Site URL?

I had an iWeb blog https://www.turtlevines.com A month ago I created a duplicate blog in wordpress since I wanted them to run at the same time while I was debugging I had the wordpress site and home URL to be https://www.turtlevines.com/blog. Now I only use the wordpress one for updates. I have turtlevines.com hosted with sonic.net.

How can I now eliminate the iWeb and change the wordpress to turtlevines.com? Thanks for any help you can give…