Step 10 · Reconnect P-Trap to New Drain
Align the P-trap with the bottom tailpiece of the new shower drain. Make sure the slip nut and the tapered plastic compression washer are on the P-trap pipe (tapered end facing the drain). Push the P-trap up to meet the drain and hand-tighten the slip nut. Use channel-lock pliers to give it a final quarter-turn to ensure it's snug and the connection is watertight.