Ignition actuator broke, truck will not turn off

The ignition actuator on our truck broke. However, the symptom of this problem has had an opposite effect on our vehicle, it will not turn off. We have to disconnect the starter switch to stop the vehicle.

We have opened out the steering column from the steering wheel and see the broken ignition actuator piece. Many have suggested that you can cut the small box at the end of this piece to install the new one without tearing down the whole steering column.

I want to make sure that this small box does not have an important function.

Does anyone have a blowout diagram of how the end of the ignition actuator "arm" interacts with other parts of the steering column? Or have some insight as to the true functionality of the box structure at the end of the ignition actuator? Please note that "arm" is not referencing the rod that hooks into the ignition switch, but the arm that extends out of the curved piece of the ignition actuator, into the steering column. See picture.

Thank you.

Sarah