This step requires a notch to be made in the bow for later placing the stem. Instructions just tell you to use a flat file to do this. But...first place the stem (shown) on the bow and lining it up in the center, draw a pencil line on both sides as a guide for the notch. Then use a box cutter to score inside both lines. Do this repeatedly until through the thickness of the hull strips. Use the X-ACTO knife to chip out the notch. Now use a flat file to deepen and smooth the notch until the stem fits properly in the notch without rocking.