I own the domain zenstealth.com and I have decided that the easiest way for me to "do" a blog is via GitHub pages and Jekyll, which is already built-in in GitHub pages. I've done that already, and for now I've already setup a CNAME record so that my GitHub pages repo zenstealth.github.com redirects to blog.zenstealth.com.
What I want to do is instead of using a sub-domain for the blog, I'd like to make it use the top level domain zenstealth.com. The GitHub Pages instructions say to the set an A record to the ip 18.104.22.168. The problem in NearlyFreeSpeech.NET (let's call it NFSN for short) is that it already already sets A records to files which are hosted directly in NFSN, and I have absolutely no idea on how to override this.