2. Cut each sleeve open along the seam. Fold in half lengthwise and cut along the crease. You should have four pieces total.
3. Arrange pieces end-to-end, wrong side up, on a flat surface. Make sure they are all going in the same direction, so that each hemmed end is next to a raw end. Overlap the pieces ½”, so raw edges are on top of hemmed edges. Glue pieces together to form a long strip. Working on length of strip, fold one edge under (toward wrong side) about ¼” and glue in place. Leave other edge raw. Fold short ends under about ¼” and glue in place.
4. Turn shirt right side out. Align one end of strip with a shoulder seam, right sides together, and pin so that raw edge of strip and edge of collar are aligned. Continue to pin edge of strip to edge of collar all the way around. Trim end of strip so it overlaps about ¾”. Working in small sections, glue cowl strip to shirt, about ½” in from collar’s edge. Glue ends together so they overlap.
5. Turn shirt wrong side out. Fold cowl strip over and pinedge to inside of collar. Working in small sections, glue pinned pieces together, about ½” in from collar’s edge.
6. Iron collar to make a crisp fold.