Changing from blog.mydomain.com to mydomain.com

So long as you take a backup of EVERYTHING first, you can always back it out ?? Remember that. Tattoo it on your brain. Never forget it ??

I would do this:

1) Change the blog address to https://mydomain.com

2) change the Site address to https://mydomain.com/blog

3) Turn off the subdomain for https://blog.mydomain.com on your Cpanel or whatever

4) Remember to move your .htaccess from https://mydomain.com/blog to https://mydomain.com/ (and copy the index.php over like you normally would for a move).

5) In your .htaccess at https://mydomain.com/blog put this:

# SubDomains
RewriteCond %{HTTP_HOST} ^blog.mydomain.com [OR]
RewriteCond %{HTTP_HOST} ^www.blog.mydomain.com
RewriteRule ^(.*)$ https://mydomain.com/blog/$1 [R=301,L]

This will redirect anyone who goes to blog. to your main domain.

6) Search in your blog DB for any remaining references to https://blog.mydomain.com and replace them with https://mydomain.com/blog (mostly this will affect images)