Place the housing on top. Notice I have 3 longer screws and one shorter one. 3 holes go through the housing while one doesn't near the motor, I could have used all 4 short screws but I was using what I had laying around my shop. Insert and tighten the screws.
Hold the cable firmly to prevent it from twisting and push it into the housing. When it's almost completely in, slide the mast housing tube over the mast and push it down into the housing until it stops firmly. Tighten the set screw then push the mast all the way in.
Replace the motor and tighten it's two screws.
Replace the silver mast-to-motor bracket and tighten the screw in the middle.
Put the power mast assembly back into your car and plug in the power wires and the antenna cable. Have a seat in your car and turn it and the radio on and observe the antenna. Turn the car off, pull the key and open the door...Admire your antenna as it retracts again as it's supposed to! After doing this my antenna is a LOT quieter than before and I can't hear it at all even.
Make sure your ground strap is connected like this: