18. Then the piece of glass is turned sideways and slid into the door through the top. Slide it down into the door and turn it right ways. I leave the lower mounting bolt of the front channel out as I install the glass into the rear, then the front channels. Then install the lower 1⁄4-inch mounting bolt. Once the glass is in the channels and the front one is secured, position the glass into the mounting clamps and tighten the nuts.