change the assignee for a closed loop survey tickets

We have a worklow in qualtrics which creates closed loop tickets on the imported data on conditions like low nps score. These closed loop tickets are assigned to specific UNIT_ID/user ids which get hardcoded, we have got requirement from our business to make these user ids changeable such that any user to whom these tickets are assigned can manually go into Qualtrics  ticket and change the assigned user to someone else. Please help suggest if there is any custom coding/java script/change in work flow that we can use