That's it. When you start the game now, the item's quality will be iconic.
What the fuck did I just do?
You created a tweak edit.
Removing properties
If you want to safely delete a record property, set its value to None. For example:
You might not want to actually do it.
Adding attachment slots
To add attachment slots to an item, you would need to change its blueprint property by either using other blueprints or create a new one using this guide