DBCC dllname (FREE) (Transact-SQL)
SQL Server 2005
Unloads the specified extended stored procedure DLL from memory.
Transact-SQL Syntax Conventions
When an extended stored procedure is executed, the DLL remains loaded by the instance of Microsoft SQL Server 2005 until the server is shut down. This statement allows for a DLL to be unloaded from memory without shutting down SQL Server. To display the DLL files currently loaded by SQL Server, execute sp_helpextendedproc