You can put a BMW in neutral with a dead battery using two methods: get under the car and disengage the latch or disengage the transmission from inside the vehicle.
To disengage the transmission from inside the vehicle, follow these steps:
At this point, the transmission is disengaged for 15 minutes, after which it will re-lock. If you need to keep the vehicle in neutral, you may have to physically disengage the transmission by going under the car and turning a screw until it disengages.
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