installing WP to IP address only

I’m working on a replacement site for an existing site and considering WordPress for the entire site, not just a blog. I installed WP and when I set it up I entered the FUTURE domain name. After the install I could pull up the index but couldn’t get into the admin because WP is now trying to look up the admin via the existing domain location. I edited the wp-config.php by adding the suggested lines with my IP address as entries but it doesn’t go.

SO I’m sure there are lots of WP developers out there that have this down to a science .. developing a site on an IP and moving it and editing it for a domain location.

Tips for installing to an IP address only? I can easily uninstall and reinstall at this point.