Electrostatic printing processes utilize corona-charging units. When those units wear out or become faulty, they need to be replaced. This embodiment provides a tool that can be used to remove a faulty electrode wire assembly from the unit. This same tool when loaded with a new wire assembly can insert a new wire assembly into the emptied corona charging unit, sometimes referred to as a dicorotron unit. The tool, therefore, is used both to remove or insert a wire assembly from or into a dicorotron unit.