i recently did same, i called the smartobject event and Update status to reject or approved based on Outcome in workflow.

Hey,

if if you are trying to change the action from approve to reject for already completed instance as out of the box it's not possible and you can only do that through SQL scripts by querying data tables of SERVERLOG schema but it's neither supported not recommended by K2 and thus I would recommend you to not to do that!

but if you have got your own application database and there if you have maintained these status values there you can do that as these DB are under your control.

hope it helps,

cheers,

Prajwal Shambhu