Addition to previous upgrade to 3.0.4 fatal error

I tried replacing the taxonomy.php file via ftp but this did not work. I now have no way accessing my wp-admin dashboard only by ftp. I have the old files backed up but don’t know what to replace so that our site comes back.

When I go to our URL – https://www.thebabycakery.co.uk – all I see is the fatal error message!

Please please can some one help me

Ian