Q: Is there a way to change their user type?A: NOQ: If not can I delete them and then create a new account for them as a user?A: YesQ: if I delete them what effect does that have on tickets that they closed?A: When I look at our osTicket, the only thing I see that changed after we deleted on of our former agents (John Doe) was that the "closed by" field is then empty. But in the history you can still read the the ticket was closed by "John Doe", so shouldn't be a problem.