That's great that you've finished most of the hat. How many sts do you have left? Toward the end of the hat you've cast off the cable sts on one side (row 81) and then work the cable on the other side. Finally you cast off that side too (after row 92). You can use this bind off
for these two sections or, if you'd like you could leave the sts on holders and use a 3-needle
bind off here. The two cable edges get sewn together (or joined by the 3-needle bind off) and then you start the scarf separately. The final step is to join the middle of the scarf to the cast on edge of the het.