My AC/Heater motor started buzing this afternoon. Been 103 plus for the past seven days. It even shut down for a time. We stopped for dinner this evening and when we came out it started again. How hard is is to change one out? Given I have only one usable arm due to surgery I'll probably have it done at a shop.

Its easy to see under the glove box. I believe its 3 screws. check this out

https://www.youtube.com/watch?v=1vYTSyJiAIQ

Mine started buzzing early spring '15. Then airflow almost stopped. After dropping blower motor (as said, pretty easy) , the buzzing was a piece of the recirc door that had dropped into the blower cage. The airflow stopped because the door fell out and was laying on top on the blower.
Not too hard to replace but about 2 days later the a/c clutch went out.



Tim