How do I install the Honeywell RTH5160D1003 thermostat?

First, turn off power to your heating and cooling system and remove the old thermostat, labeling all wires. Mount the new thermostat base to the wall using provided screws and anchors, ensuring it is level. Connect each labeled wire to the corresponding terminal on the base, then attach the thermostat to the mounted base and restore power to your system. Finally, use the up and down arrows to set your desired temperature and select the appropriate system mode.