Changing links messed up admin login redirection

I was changing some settings and accidently made a mistake that i cant seem to undo. I was changing titles and headers, and accidently changed a field that made all root links point to an unregistered domain name. The site has worked for months. Its just a link issue.

Links and files were found at http://www.massivemonkees.com\filepath\etc now they point to http://www.massivemonkeesblog.com\filepath\etc.

When I try to go to http://www.massivemonkees.com/wp-login.php, I can get to the login page, but logging in forwards me to http://www.massivemonkeesblog.com/site/wp-login.php which doesnt exist.

When I go to http://www.massivemonkees.com, the page shows up but with out CSS formating and complains about 404. When I view the source, I can see that all the scripts point to the wrong location (www.massivemonkeesblog.com) which explains the 404.

So, heres the problem. Once I changed that setting, I can no longer get back into the admin page to put it back.

What can i do to fix this? Can I fix this through FTP?