If you have to take the whole thing out to fix it, it is a BIG.....but do-able job. I had to put a heater core in our 2004 Dakota, which should be the same thing. You have to drop the steering column down, and remove the whole dash to get it out. If you end up having to do that....I would strongly suggest replacing the heater core and AC evaporator core while it's apart. The controllers are all electric on mine, and I set the dash control to one setting (floor heat), took pics of everything and made a bunch of drawings and notes before taking the box apart. I put it back together so it matched up with drawings and pics, and it works perfect. Good luck to you!