Don't know if it was on this forum or a "well known" other Dodge forum, but someone posted up a "how to" on this. Complete with step by step pictures and parts needed etc.
Do a search here and you might come across it.
Needless to say, as SeVeReDiStOrTiOn said, It's not a simple thing to do and will take a weekends work at least, to someone who hasn't done this before.
Aparantly, it's the plastic limiting pegs on the doors that stop the actuators on the blend doors from going too far, that snap off.
There is an upgraded part for this I believe. I think I remember that all the bits from the dealership were about $130 or so.
Hope this helps?
Al.