How to transfer CNAME domain to new project?

I am using my main Github page (myname.github.io) as a portfolio, which redirects to a custom domain (myname.com). However, I made a completely new portfolio in a different repository which is currently live as a project page (myname.github.io/new_portfolio). I want to use myname.com for my new portfolio project instead of my old one.

My CNAME is a Google domain, so it is linked to “myname.github.io.”. I am not sure what needs to be changed where. Do I need to change “myname.github.io.” to "myname.github.io/new_portfolio." in the Google Domain dashboard? Or do I need to somehow transfer myname.github.io to my new portfolio project? How can I do that through Github?

Basically I want my current Github user page to change to myname.github.io/old_portfolio and mhname.github.io/new_portfolio to change to myname.github.io

It should be fairly simple to do this but you’ll need to rename your repositories to do this.

First of all you’ll need to detach your custom domain from your current repository. You can do this by visiting the repository settings, editing the custom domain, and deleting it deom the input box.

Next you’ll need to rename this repository to something other than gvholley.github.io–perhaps rename it to old-website or something.

Finally, visit your new repository. You’ll want to rename this repository to gvholley.github.io. Then you’ll want to attach your domain name to this repo instead. You may need to refresh the settings page and enable GitHub Pages after renaming your repo, but you should be able to add it in the custom domain input.