Place the new pocket fabric inside the pants, positioning it where the original pocket was removed.

Make sure the fabric is evenly spread out and flat to avoid wrinkles or bunching.

Compare the position of the new pocket with the other pocket and the original stitch marks, to ensure it's placed correctly.

If you're unsure about the placement, use the cut-out pocket as a reference.

Use sewing pins or clips to temporarily hold the fabric in place while you prepare to sew.