Industrial Hobbies Brill Trolley: How do you disable the E-unit?

[marmelmm]

I've got a couple of these cars, and have run into minor problems at shows where the kids will shut the car off and then be confused when it goes into neutral and not move. Is it possible to bypass the E-unit and make it bump-and-go only?

Thanks!

VTY,

-MMM-