Unclog bathroom sink without chemicals

Step 8 Reattach popup assembly

After scrubbing your stopper and drain hole clean, place stopper back into drain hole with flat area and connection hole toward the back of the sink, so that side is closer to the lift rod.

Hold up the stopper by a cm or so with one hand, while reaching under the sink with the other hand adjusting the horizontal rod to get that plastic shaft into the hole at the bottom of the stopper so they are connected.