You can remove a trigger by dropping it or by dropping the trigger table. When a table is dropped, any triggers associated with it are also dropped. DROP TRIGGER permission defaults to the trigger table owner and is not transferable.
(For details, search for "dropping a trigger" in SQL Enterprise Manager Help.)
Or
For example:
DROP TRIGGER deltrig
drops the deltrig trigger from the sales table.
(For details, see the DROP TRIGGER statement in the Microsoft SQL Server Transact-SQL Reference.)