1. Set the database to Single User by right clicking the database in Enterprise Manager, select Properties, select the Options Tab, check the Restrict Access checkbox, and select Read-Only, then click OK.
2. Close Enterprise Manager (since we can only have 1 user accessing it at a time now).
3. Open Query Analyser.
4. Type: sp_renamedb
5. Don't forget to reset the Restrict Access settings on the database that you changed in step 2.