Removing an Extended Stored Procedure from SQL Server
To drop each extended stored procedure function in a user-defined extended stored procedure DLL, a SQL Server system administrator must run the sp_dropextendedproc system stored procedure, specifying the name of the function and the name of the DLL in which that function resides. For example, this command removes the function xp_hello, located in a DLL named xp_hello.dll, from SQL Server:
Beginning with SQL Server 2005, sp_dropextendedproc does not drop system extended stored procedures. Instead, the system administrator should deny EXECUTE permission on the extended stored procedure to the public role.