Zaxbee

I'm trying to alter my ID to change my TSV and want to make it a legitimate ID to obtain. I just wanted to edit my ID and SID and hopefully generate the correct G7TID based off of that but I can't seem to do that in PKHeX. My only options are to edit the G7TID and an SID field with only four digits. Can anyone help me out here? How can I edit my ID's to obtain a legit one for the TSV I want?