1. Before entering upon the duties of their office each of said commissioners shall take and subscribe an oath, which shall be filed and kept in the office of the city clerk, to support the Constitution of the state of Missouri and to obey the laws and aim to secure and maintain an honest and efficient force free from partisan distinction or control, and to perform the duties of his office to the best of his ability.

2. Nothing in this section shall be construed to authorize the commissioners to remove or discharge any chief, as that term is defined in section 106.273.