Im not mentioning starting it
With traditional automatic, once the engine stops the car can roll in any gear except park (which locks the ring gear), and a provision is provided to move the stick out of park without battery power too. Even on cars with electronic lever the gear can be released from park with either a special tool or by turning a bolt and manually forcing the pawl to unlock.
My point was, if the ags car is now dead and was parked in gear you definitely need to use a booster pack to engage neutral.
You almost always need to move the car to a favorable position to replace battery.
Or
How will a tow truck driver tow it if the battery is flat? Find a jump pack (almost all of them dont own one in Pakistan)