Update the Metadata for all Documents

First you need to find the MySQL username / password for the site you want to update.

Then you need to do something like this:

mysql> select Publisher from Document;
mysql> update Document set Publisher='MKDoc Ltd., 31 Psalter Lane, Sheffield, S11 8YL, UK.';

If you haven't used MySQL on the commandline before then the MySQL web site might be a good place to start.