Whoops, I misread this. You just want to move the database (.mdf & .ldf files) to a new disk? In that case this is not really a Backup Exec task, but more a SQL Server or MSDE thing. The basic idea is to shutdown the Backup Exec services, detach the database from the SQL server/MSDE, move the .mdf and .ldf files to your new location, and then reattach them to the SQL Server/MSDE.
A quick look on the net shows a similar sort of thing for Sharepoint Services
here, which should give you the idea of what you're trying to do. I would have though the Symantec knowledge base should have better instructions there somewhere.