Q: Moving from subdirectory and subdomain -> root Background: I've only done vanilla theme and direct installs until now. The site I'm working on has an existing (ancient) Mambo install in root directory. For the new Wordpress revision, client wanted to develop the content of new site before replacing it. After reading the Codex, I decided doing a subdirectory install was the best way to go, then use the pre-existing subdirectory install routine to move it to root. But for some irrational reason, instead of just pointing to the subdirectory, I assigned the new Wordpress site to a subdomain. (I'm new at this, and now realize I made it more complicated than necessary!) 
To summarize current situation:
www.example.com --> existing old site
www.example.com/wordpress --> WP physical install
dev.example.com --> Subdomain is assigned to www.example.com/wordpress; WP URLs assigned to dev.example.com
After reading the procedure carefully, I plan to proceed this way:
0) Backup database and full install folder to local
1) Change WP assigned URLs to www.example.com
2) Remove the subdomain pointer
3) Copy index.php and .htaccess to root as normal (I will back up the old index.php and .htaccess to a subdirectory in case I have to fall back to the Mambo site).
4) Change index.php's require('./wp-blog-header.php'); to require('./wordpress/wp-blog-header.php');
1, 3 and 4 are standard. I'm hoping that by removing the subdomain assignment in sequence at 2, there will be no issues with this. My question is: does that sound right? My concern is that removing the subdomain will nuke the /wordpress folder or do something else crazy. I haven't done that before, and the client's site is on 1and1, which has a very obtuse nonstandard back-end.
Thanks for any advice.

A: If I understand you correctly, you're removing the old Mambo site and intend to run WordPress as the main site in this domain.
If that's the case then (depending on any plugins that you have running) all you will need to do after making backups of everything is move the entire contents of your /wordpress directory up to the webroot and run a search and replace on the database for the string 'dev.domain.com', switching it for 'www.domain.com'
Do bear in mind that this last step is thoroughly dependent on the two strings (dev.domain.com and www.domain.com) being the same length.  If they are different in length, for example 'staging.domain.com' and 'www.domain.com', then you may be better served by a tool such as the incredibly useful Search & Replace for WordPress Databases by Interconnect IT
