Once I decided how best to angle/align the dowels/skewers with the front and rear square stock that form the LE and TE of the vertical fin, I used an awl to mark and start a pilot hole, then drilled the hole to accommodate the dowel.
Apply thick CA into the hole and insert the skewer. Be careful not to go so deep on the rear skewer that it causes interference with proper placement of the top rudder hinge.