Build a Ground Force Training Facility on Mars, design an INF-HQ unit (of the defualt capacity 1000 tons), design an INF-PWL unit, Research both and design a formation template of one INF-HQ (size 10 tons) and 330 INF-PWL (size 3 tons each).
Train your new 'Home Guard Company' or 'Auxiliary Police Volunteers' or 'Friendly Persuader Detachment'.