Find the midpoint of each sheer (see Pirogue Materials & Cut List for sheer demensions) and mark it. Find the midpoint of the hull sides and mark those. Align the mark on the sheer and the mark on the hull, while holding the sheer against the hull side top edge with the rabbet over the top edge, roll the sheer to each end ensuring that there will be overhang on each end.
The instructions provided on this website are not always detailed enough and are "my way" of doing things. Ask 10 different boat builders or woodworkers how to do 1 thing and you'll get 10 different answers.