Have an 06 Durango 4.7 completely stock.

Front blows warm air when air conditioner is on. Once I turn on the Rear Air, the car starts blowing colder air in front, but not as cold as rear. I have been seeing some threads here and there talking about the AC Blend Door actuator. But I don't know if anyone has actually corrected the problem by having it replaced. Or better yet, any instructions to do so.

Anyone?