Probably not. It is connected to a circuit board. You can easily make it stop counting hours by ripping it off the board. The hard part would be getting it working again. I won't even get into why you want it to stop counting.
That's exactly what the OP is wanting to do, or should I say his brother-in-law wants to do. The OP emailed me telling me that, and I PM'd him/her back saying I wouldn't comment on whether it would work or not, nor would I condone the practice of essentially rolling back the odometer.