Jeep Repair: 1999 Jeep Grand Cherokee - Blend Air Door needs replacement, jeep grand cherokee, air doors

Question
I took my Jeep to a Dealership today because it was not blowing hot air.  It would only blow cold air and would not change from feet, to defrost, even when in "auto" mode.  The dealership stated that all the codes were indicating i would need to replace the blend air door and it would cost right at 1150 to fix.  My Jeep is a '99 with 123000 miles on it.  My step-dad was going to try and see if it was something he could fix as he does all his auto repairs at home.  Is there anything you can suggest as far as parts go or reliable manuals?  After doing quite a bit of research I can see this is a very labor intensive job.

Any help is appreciated at this point.  Thank you for your time.

Many Thanks,
Kelli

Answer
I would get the parts from the dealer  unless U know they are the updated parts  the blend air doors and the rec door is around 200 from the dealer. The whole dash will need to come out as well as the HVAC housing will need to come out and split apart  first time  it would take about 6 to 8 hours to do this sorta job. I dont know the extent of the manuals if they are good enough for this job.