DBCC dllname (FREE) (Transact-SQL)
SQL Server 2008 R2
Unloads the specified extended stored procedure DLL from memory.
When an extended stored procedure is executed, the DLL remains loaded by the instance of SQL Server 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.