Chevy Cavalier heater switch

Chevy Cavalier

My 2004 Chevy Cavalier has a heater related problem. The heater works fine. The variable strength switch works fine. The heater directional switch does not work. No matter where the switch is placed, the heat comes out the front. This is highly inconvenient in the winter. Is this a problem that needs to go to a dealer or something I can try to fix myself.