[sql-server] How to find all trigger associated with a table with SQL Server?

select m.definition from sys.all_sql_modules m inner join  sys.triggers t
on m.object_id = t.object_id 

Here just copy the definition and alter the trigger.

Else you can just goto SSMS and Expand the your DB and under Programmability expand Database Triggeres then right click on the specific trigger and click modify there also you can change.