Open up your editor.
Find the 'Custom Rules' line in the Menu. I'm at work, and don't have the editor in front of me, but it's the second or third option on the right.
I don't remember if it's in the properties tab, or if it's under the custom rules, but hunt around a bit, you'll find it. I think it is in the Properties, but not sure.
Make sure you save it as a scenario. Something you can remember for later, like Debug.Bix or somesuch.
Open PTW, click on Load Scenario, find Debug.Bix (if you called it that) and load it.
Then play. Never used it, but it there. . .