One of the weaknesses of WordPress and most other web-configured applications is that unless you want to go SQL or config-file-wrangling, it’s pretty much only configurable via the web, at least for tweaking, importing posts, setting up most of the options. This is a problem when, for instance, you’re migrating an existing site onto WP, and it’s on a new server, as you can’t get to the wp-admin screens.
The way to do it is to hack your hosts file. Once the new server is running and WP is setup on it, find your hosts file and add an entry to the new server. On Windows, this is the c:\windows\system32\drivers\etc\hosts file.
Chuck in a line that says contains your new server’s IP address, and the hostname. Something like:
(Whoopsie, real-world example with a fake IP. The new evision site is going live Real Soon Now.)
Save, then away you go. You can see the new site and tweak to your heart’s content, but nobody else will be able to see any of it until you re-delegate.
The catch? It probably won’t work from behind corporate networks, where your computer uses a proxy.