I would like to cahnge/update a merge code but am not able to fine the right place to make the edit.
It depends on where the merge code is that you want to edit. If it is in a survey question, you can click to edit the question in the build section and you can edit the merge code there. If the merge code is in an email message in an email campaign, you can edit the message inside the email campaign in order to access the merge code to edit it. There’s lots of places merge codes can be, so it just depends on where it is and wherever it is, you just edit that.
The intro to our document here is a good step to getting started on where to find merge codes to add/readd them:
There is also a list of the merge codes that can be used in SurveyGizmo. It’s a great place to see what is possible and how to make it happen with merge codes