85 chevy pickup window and regulator replacement

I have the panel off......I now see just the metal housing in front of the motor and regulator........how do i get at it for replacement? It seems like it should be easier than this.........

I just know that on some vehicles you have to drill out rivets that hold the window to a plastic guide that slides on the regulator and then drill out the rivets that hold the regulator to the door and replace with nuts/and bolts if clearance is there or re-rivet.