Changing Queue Topic/Topic Group once request is submitted

We have several instances where users have selected incorrect queue topic or topic group on their requests. Currently, there is no way for the user or Admin to correct this error. Even if the user re-enters the request with the correct information, there is no way to attach the corrected request to the project to replace the incorrect one. There should an option for users to go back and select the appropriate information if they make a mistake.