Now is a good time to look at the various light bulbs in the unit and try to replace them if necessary. My unit had no issues, but the parts unit had 3 bulbs burnt out. Replacing these will prove to be challenging as they are very close to the posts and almost inaccessible.
It's also a good time to check the bulbs in the switches themselves, as there are no fewer than FOUR in the Defrost/Recirc one (!) Again a thin screwdriver is used to pry the back off the switch casing. Be careful not to lose the springs.
After disassembling the parts unit in the same fashion, the good mounting plate is snapped into the front of the unit and the switches carefully inserted through the PCB. I had to clean up the PCB holes and the switch posts with the soldering iron to make it so that things went together easily.
Carefully solder the switches back to the PCB, making sure not to heat up the switch posts too much.
I used hot glue to hold the PCB's together instead of the original urethane.
The unit all reassembled and ready to go back into the car.
And finally like it should be again!
This is certainly not for everybody, but if you are handy with a soldering iron it is not so hard to do.
Cheers, Keith