heat control

[barks507]

I cannot control where the air flows into the cabin. I recently discovered I cannot turn heat down but figured that out to be an actuator above glove box. While I was checking that out I noticed another broken piece. It is a white nylon piece connected to a metal arm that goes into a diaphragm (vaccuum controlled). I need to replace that plastic piece but cannot find any info on how to get at it or find a replacement.