Create an animated Aircraft Wheel Change Dolly

To create a 3D animation of an Aircraft Wheel Change Dolly. The animation must demonstrate that the floor panel is being lowered so that the wheels can be removed from the dolly including the axle jack. It must demonstrate also how the replaced wheels and axle jack will be returned from the dolly so that the floor panel will be raised up on its original position. The dolly also includes nitrogen bottle which is stationary.