RV Repair: Atwood 8525 II, plastic blower, blower wheels

Question
I have a problem with noise.  The unit screams upon startup, then quites down.  I suspect blower motor needs replacing.  Do I have to remove the unit from the trailer, if so how do I do this?  Incorrect procedure could damage something.  I am a qualified industrial instrument tech so I think I can do this repair, but I would like to have some advise on it.

Answer
Hi Harold. You are right. The motor is bad. I think that this can be done without removal of the entire unit. It all is accessible form the front. Removal or all the plastic blower housing and blower wheels must be done carefully. They tend to brake if stressed. Good Luck.