1. You can use Visual Studio Schema Comparison.
2. You can use some replication third party tool that merges the content between your development and production. Generally it synchronize all changes between staging and production database.
3. Update staging and production databases directly from SQL Server Enterprise Manager or SQL Server Management Studio ( this could cause a lot of problems if something goes wrong)
Sitefinity 4.0 will come with built in comparison tool between your staging and production.
the Telerik team