| It is actually pretty easy to do..
1. disconnect battery (very important of you can trip the airbag light).
2. Remove seat
3. Pull back carpet and remove cover plate.
4. Disconnect unit and remove.
It is a box that can be pulled out easily and the connectors on the back can easily be removed. After that you could open it up and blow out the dust to see if that helps. If it still won't work after you clean it all up, then you are going to need a new unit. | 
