Domain mapping plugin

It’s not that hard. It does take a few st3eps, but it’s nothing that can’t be done pretty easily. You can find a great guide at Moving WordPress.

Is there no other option?

It says in this part of the codex that I should be able to keep wp in its own folder and run in from the root directory, even with multisite. But it isn’t possible to follow the directions with the multisite dashboard.

It is possible to run a notwork from a sub-folder. I’ve done it before so I know it works. The only thing that comes to mind that might block that somehow is your .htaccess file, so I’d try that first.

I already tried moving the installation to root according to the guide you gave before. Unfortunately, something is truly screwed up. I can’t get the admin page (or anything other than the frontpage of the main site) to load.

It’s at theslowroad.org

Looking at that you need to update the sites URL in the database. Your site looks wrong because it’s still trying to load everything from the old URL.

The best tool that I’ve found for that so far is this. Run that and enter the right values and it will get your site back to working again.

Do I install that in the same folder as wordpress?

Yes. To make things easy it should go in the same folder as your wp-config.php file.

Oh, and remember to delete it off the server as soon as you’ve finished with it!