Using your new 2P Brushed Gun Metal Mica Shower Mixer with Diverter is a breeze. To switch between shower and bath modes, just use the diverter. Turn it one way for the shower and the other for the bath. When adjusting the water temperature, turn the handles slowly to avoid sudden temperature changes. As for maintenance, clean the mixer regularly with a mild soap and a soft cloth. Avoid using abrasive cleaners as they can scratch the brushed gun metal finish. Also, check for any leaks periodically. If you notice any, it's best to call a professional plumber to fix it.