Ok so I decided today to change the rotors & pads. After I removed the wheel then disconnected the negative terminal and removed the 2 parking brake caliber bolts I could not remove the Pbrake caliber due to the deeply worn rotor.
On the inside it is twice as deep as the outside. So I obtained a grinder to relieve the edge to allow the pads to slip off the rotor. But...

I have to have the car in neutral to turn the axle. So I tried a couple of different way to get the car in neutral and turn off the ignition. Not possible the car does not allow you to do that. Human proof.

So my question is what harm will come if any, if I leave ignition on, leave in neutral and remove the negative terminal?
I don’t want screw the CCU or something else up. So I’m at a stand still until I can get some additional.
info. Any help would be appreciated.
Thanks in Advance!