Just found this simple and quite useful plugin called Change Blog URL by Kt that allows you to change the URL of your WPMu blog with one click. I tested it out on UMW Blogs and it works flawlessly with version 1.25a.
This plugin allows blog user to change their blog URL from existing one (subject to availability). The admin page can be access at Option->Publishing. This plugin simply modify 4 fields, three fields in user blog option table and one in the wp_blog table. When user enter a new blog address, the plugin will check for rule that apply when one sign up for a new blog.
Does anyone know what those four fields are? I’d like to do this manually.
You would change the subdomain in wp_blogs table.
And then in wp_#_options three times (where the # sign is the id of your blog you are changing the URL for) make the following changes:
Change the siteurl’s option_value to the new subdomain
change home’s option_value to the new subdomain
And change fileupload_url’s option value to the new subdomain
I think that will do it. Keeo in mind this is for sudomains, not mapped domains.
Let me know how it goes.