Can't turn it off. Not without a change to the rule. That's the whole point. If you are equipped, no matter your aircraft, you cannot move the airplane anywhere within the boundaries of the USA without the equipment being turned on and operating. No exceptions. This includes an engine run up, taxiing on the ground, or landing to pee in the middle of nowhere. Any time, any where, any how. Make sure your local maintenance shop knows that when they start or move an equipped aircraft for any reason ADS-B out must be on and operating properly whether they are in or out of Rule Airspace. You can turn off ADS-B physically, at which point you are in violation of the FARs.