Delete users for GDPR, but keep historical data as anonym

Question

I'm trying to find a solution. To find all users, which have been not active for a period or not at all active.

I can see the UI have been change. So i had to find the customer, with this help => Solved: Can't find portal customers in Jira service manage...

But i cannot delete the users, through the API. When i try as the documentation says 
I get this

Error publishing web request. Response HTTP status:400

Error response HTTP body:

{"errorMessages":[],"errors":{}}, {"errorMessages":["Cannot delete user because 1 issues were reported by this person.","Cannot delete user because they have made 1 comments."],"errors":{}}, {"errorMessages":["Cannot delete user because they have made 4 comments."]

I would like to delete the user, but keep the history as anonym.

Mads Illemann · Answer

I can only change the Displayname on the portal customer.

So right now, i can only delete a customer, through the UI.

It seems like, there is nothing to do. 
I cannot get the comments or the issues or when they have been last active.

Marc -Devoteam- · Answer

Hi @Mads Illemann

You could create a service account and bulk assign the issues to this user.

Mads Illemann · Answer

So there is not at admin way, where i just delete the users, and the comment and stuff change automatically?

Do you have any suggestion, what user?