I know this is late coming but my bin cover just came off so… I was in the same position as you. I aligned one of the plastic tab in position or in one of the holes. While keeping the inserted pin tab in position I aligned the other pin square to the first and use pressure to push it down, it snapped in place. It takes some pressure to snap the last tab into the remaining hole. The tab plastic is tough. Remember to keep the tabs in alignment while applying the doward pressure.