Were is all the Data kept in a Multi DB Setup ?

Ok the problem

I have some old domain names that was used to set up splogs.

I would like to do a find and replace in MySQL were do i start

1) Home db
2) Global db
3) and then have a look in 4096 dbs for the sites

There must be a easy way of doing this.

Please guys just have a look trough but as far as i can see the Multi Domains keeps the data in 3 place the home / global and the blog db ...